It was a month ago when Kerry Tharp's phone rang. The area code was a familiar one: 386, as in Daytona Beach, Florida.

The man known throughout the racing world as "The Commander" is in his fifth year as president of Darlington Raceway, NASCAR's old-school equivalent to Fenway Park or Lambeau Field and a facility that, as of last fall, is owned by the sanctioning body itself. Before that, Tharp spent more than a decade in NASCAR's communications department. So, when the phone rings from 386 and NASCAR headquarters in Daytona Beach, Tharp has always known it is never an unimportant call.

But this one was the biggest he has ever answered.

"They said, 'Could Darlington be ready to host a Cup Series race on May 17?'" Tharp recalls. "I said, 'Well, I don't seem to have anything on my calendar for that day -- or anything on my calendar for any other day, either. So yeah, let's do it.'"

The Commander laughs as he tells the story, then quickly cuts those chuckles short.

"For a month I had been just like everyone else in the United States," he said. "I was at home, on my couch, doing whatever I could around the house and wondering when we were going to get sports back. But as soon as I got that phone call, I called the Darlington Raceway staff and said, 'See you back in the office tomorrow morning. We've got a few weeks to do a few months' worth of work.'"

On Sunday at Darlington, NASCAR will return to the racetrack for the first time since the coronavirus pandemic forced it to pack up and abandon Atlanta Motor Speedway on March 13, as teams were preparing their cars for the weekend's first practice session ahead of what was supposed to be the season's fifth race.

Now that fifth race will be run two months later and at an entirely different racetrack. It will be held with no fans in the grandstand and no laps having been turned in practice or qualifying. Teams will do their work in unusually small groups, restricted to 16 crew members, including the driver. Big organizations routinely have three times that many people on their credential rosters, from mechanics and engine tuners to team owners and family members.

Those crew members will be the subject of a health screening prior to entering the racetrack, a check of temperature and vital signs, to be compared with health notes already supplied to on-site medical teams. As one Darlington Raceway official described it, "It'll look like the TSA airport screening line, but with thermometers." Anyone showing signs of fever or other symptoms, or exhibiting in-person deviations from the paperwork provided, will be sent for "heavy screening" by physicians in the newly erected medical center.

When they go to work inside the track, they will be subject to random light screenings throughout the day and thermal cameras will monitor their temperatures as they work. There will not be COVID-19 testing as of yet, in part because the tests take days to process and because NASCAR has said it does not want to take tests away from the general public.

Anyone who does not comply with these new unprecedented safety measures and rules -- say, a refusal to wear a mask -- will be ejected from the garage and hit with massive fines. In the garage, there will also be no tolerance for handshakes or hugging it out with friends. There will be no contact with anyone outside of one's group, every team confined to designated work areas and walking to those areas via precisely marked footpaths.

The path that NASCAR has traveled during the 65 days between Atlanta and Darlington has been anything but precise, a constantly redrawn road map that, even here on the eve of stock car racing's return, remains written in pencil, ready to react to anything that goes right or wrong at Darlington.

"The conversations and decisions that have been made during this time are no different than the decisions that have to be made by everyone right now, in every corner of society," said Eric Nyquist, NASCAR senior vice president and chief communications officer. "The news and what we know about the virus and the pandemic, it all seems to change on an hourly basis, especially during those critical first days after Atlanta. So, we have always had to be willing to react to that. And that flexibility won't stop when racing starts at Darlington. Far from it."

Those critical first days Nyquist speaks of were spent by the highest-ranking members of NASCAR's management team hunkered down in an expansive meeting space in the sanctioning body's HQ facility, located across the street from Daytona International Speedway. They have been in that room nearly nonstop over the past two months, but in the beginning, it was a strange juxtaposition, to say the least.

Only one month earlier, the racetrack across the street had hosted thousands of people as they watched Denny Hamlin win the Daytona 500 and Ryan Newman survive one of the most frightening crashes in the 62-year history of the Great American Race. Now the track, and the highways around it, were silent, as NASCAR's brass, led by president Steve Phelps, took their seats in the meeting space -- so spread apart via social distancing some had to raise their voices to deliver their talking points from one side of the room to the other.

NASCAR also was on every pandemic-related conference call that involved America's major sports leagues, including those conducted by the White House.

Over the past three weeks, ESPN.com talked with people from every corner of NASCAR, from the sanctioning body and competitors to racetrack executives and crew members, to see how they have prepared for the sport's return.

Built-in safety plan

Auto racing was widely considered a leading candidate to become the first sport to return, thanks to the lack of physical contact between competitors and an already existing emphasis on safety. It is the only sport in which competitors -- drivers and pit crews -- have long plied their trades on Sunday afternoons wearing gloves, face coverings and helmets.

Because of the dangerous nature of auto racing, NASCAR's file of medical experts was already extensive. Those contacts drove NASCAR toward Dr. Celine Gounder, clinical assistant professor of medicine and infectious diseases at NYU Grossman School of Medicine. Gounder has been on the coronavirus front lines at New York City's Bellevue Hospital Center and on the executive committee of the NYC COVID-19 Rapid Response Coalition.

"This physician had been on the ground with Ebola. What was beneficial was to have access to info that put us a few weeks ahead in terms of how we needed to respond," said John Bobo, NASCAR vice president of racing operations. "We also talked with local health care providers of where we're going, and we get buy-in from those folks. As we talked to emergency room physicians in different cities, we got a better understanding of how the virus was reacting. We were trying to find a lot of different data points.

"We wanted to go into a community that was not in crisis. We must have an advanced life support helicopter on hand, and we always have to work closely with health care providers. We treasure our local relationships with health care providers, and we always tour trauma centers before and after races. So, we relied upon relationships we already had."

Every bit of that data gathering was done with the express goal of returning as soon as possible, wherever and whenever it made the most sense. When NASCAR's list of postponed events grew from three (Atlanta, Homestead-Miami and Texas Motor Speedway in March) to eight (adding Bristol, Richmond, Talladega in April and Dover and Martinsville in early May), the target date for the sport's return became May 24, with the traditional Memorial Day weekend "crown jewel" event, the Coca-Cola 600 at Charlotte Motor Speedway.

"The attraction to Charlotte was pretty obvious once we realized that the schedule changes were going to slide into April and looking toward May," said Steve O'Donnell, NASCAR executive vice president and chief racing development officer. "It's home. Most teams can drive there in minutes, so there's no air travel and no hotel rooms. It's also the same type of racetrack [a 1.5-mile intermediate oval vs. two-plus-mile superspeedways, winding road courses or half-mile short tracks] as the races we had to postpone at Atlanta, Homestead and Texas, so race teams should have the inventory of cars and engines for that type of racetrack ready to go."

Three-dimensional chess

Even as the idea of a Charlotte return started to make the rounds, it did not deter government officials, particularly state governors, from lobbying NASCAR to pick a facility in their state to be the sure-to-be-ballyhooed comeback track. The leader of that charge was Florida Gov. Ron DeSantis, who was in contact with Phelps nearly the instant that the Atlanta event had been shuttered, assuring NASCAR it could continue to do its work in Daytona and also looking for some assurance that his state's racetracks -- Homestead-Miami and Daytona -- would still host their scheduled events, whether it be sooner or later than originally scheduled.

At one point or another, NASCAR talked to the leaders from each of the 23 states that host one of NASCAR's national series events, all with varying calendars and policies when it comes to both "return to work" and "stay at home." When asked to describe the experience, Bobo speaks of three-dimensional chess.

"This is like 18 boards," he said. "We're dealing with a tremendous number of governor's offices in a variety of states. We're looking at trends, and we know things are dynamic in communities. We have to work with our TV partners and other vendors, how are they doing and what can they do?"

For example, Toyota's race teams -- including Joe Gibbs Racing, current powerhouse of the sport -- receive their engines from Toyota Racing Development. Unlike Ford and Chevy, who build their engines in North Carolina, TRD ships them to race teams from a factory in Costa Mesa, California, where work restrictions and stay-at-home measures are still much tighter. Were they going to be able to get engines to their teams? Thankfully, enough had been delivered before the shutdown, and as of Tuesday, the TRD office in California was opening back up.

Making the restart even more difficult is the fluidity that comes with the global pandemic.

"Can Goodyear provide tires? Can we get fuel? It's incredibly complicated," Bodo said. "We're on version 65, maybe version 70, of the plan. We do have pivot plans. Frankly, there's been days of the week where things have changed by the hour."

Carolinas in the spotlight

Not surprisingly, the governor's office that NASCAR talked with most was that of Roy Cooper of North Carolina. The majority of NASCAR teams, drivers and suppliers are located in the Charlotte area, as are a pair of NASCAR's secondary headquarters, its Research and Development Center in Concord and the NASCAR Tower in Uptown Charlotte, home to the NASCAR Hall of Fame.

On April 23, Cooper designated NASCAR race shops as essential businesses, meaning that race teams could go back to work in small numbers and employing social distancing rules. But Cooper also has been among the most methodical of Southern governors when it comes to reopening plans, moving a little slower than others in the region, particularly his border neighbors in South Carolina.

That's how Darlington came into play, some 3½ months ahead of its traditional Labor Day weekend race date. With sponsors, broadcast partner Fox and team owners all pushing NASCAR to get back to the track sooner than later, the weekend prior to the Charlotte return began to look more and more attractive.

Working with Dr. Gounder, the Centers for Disease Control and Prevention, Charlotte Motor Speedway executives and local health officials already partnered with the racetrack, NASCAR submitted a lengthy "How we're going to do this" plan to Cooper in late April. He sent it back with additional suggestions and changes from North Carolina state health officials. That same plan, but with a Darlington twist, was sent to South Carolina's governor, Henry McMaster, a longtime NASCAR fan and perhaps second only to DeSantis in his constant contact with NASCAR officials to try to bring the sport back in his state. It too was approved.

On April 30, NASCAR officially announced its plans to return on May 17, kicking off seven events in 11 days at Darlington and then Charlotte Motor Speedway, four of those being Cup Series races.

"Here's how fluid this whole thing was," Tharp said. "It wasn't until a few days after we'd agreed to the first race back that we found out we would also have a second Cup race four days later. And I found about the Xfinity Series race that we're going to run in between those Cup races on a conference call right before the schedule announcement went out. I'm not complaining at all. We will host as much racing as they want. But that's how much all of this changes that fast."

It has only moved faster in the weeks since.

The new rules

NASCAR teams received the list of rules and regulations for Darlington shortly before they were announced to the public.

• No fans.

• Team rosters will be 16 people, including the driver.

• Cloth face masks are required. Anyone who does not wear one will be removed from the facility immediately and face up to $50,000 in fines.

• Teams' work areas in the garage will be spread out to comply with social distancing guidelines, as will be the spotters, who normally are shoulder to shoulder atop the press box/tower.

• Competitors' motor homes will be allowed in the racetrack infield, but instead of occupying one enclosed area, they will be spread out throughout the infield.

• Over-the-wall pit crew members will use face screens or neck socks in addition to their normal gear of firesuits, helmets and gloves.

• Teams must closely monitor the health of their employees before, during and after each event, including filling out medical forms that will be reviewed by medical personnel prior to track admission during a prerace screening that will include temperature checks.

• There will be random temperature checks of everyone working in the garage area. Anyone determined to be symptomatic will be checked via an outside care center. If they are determined to be a potential virus threat, they will be replaced with another crew member.

• Everyone is required to maintain a contact tracing log, manually and then via digital logging. If a worker shows symptoms, that person and those he was in contact with will need to self-isolate.

Teams already had the Darlington-Charlotte schedule in hand before it was made public, as well as a tentative schedule through the middle of summer. Now, with the health regulations in place, they could get back to work.

"I have literally not left my house since this whole thing started," said Hendrick Motorsports crew chief Chad Knaus, who currently oversees the cars of William Byron but won 83 races and seven Cup Series titles calling the shots for Jimmie Johnson.

Knaus is a notorious workaholic, known to sleep in his office at the height of his success with Johnson. But for two months, he has had to balance that work from home, alongside his 20-month-old son and his wife, who is expecting another child this summer.

"We have two distinctly separate groups working on our race cars," Knaus said. "There have been people at the race shop for a couple of weeks, preparing the cars for Darlington, Charlotte and beyond, but I will not see them unless it's on video. I am with the group who does not go to the shop but will go to the racetrack."

Maintaining a distance

The shop team will load two race cars -- a primary and a backup -- into the team's 18-wheel mobile HQ. The team's truck driver will arrive, entering through a door where he sees no one else, and make the 105-mile drive to Darlington on Saturday. Normally, the 40 team trucks are packed into a small space, fitted together tighter than Tetris blocks. At Darlington they will be spread out. After scrubbing down every flat surface in the hauler's work areas, the hauler driver will take on his Sunday pit crew duties with the road crew having had no contact with the shop crew.

Because of the close proximity of the track, no one will be spending the night, especially not the race car drivers -- but they will have their motor coaches on site, where they live with their families during non-pandemic weekends. On Sunday, the drivers will be alone in those RVs, purposely isolated and waiting to be called to their cars for the green flag. Those motor coaches will be wheeled into the racetrack on Saturday and spread throughout the spectator-free infield. The rigs then with get a deep clean before the racers move in the following day.

"I will be totally on my own," said Johnson, reminding that, like any other athletes, racers have a support system of people, from PR reps to agents to cooks. "I am in charge of my gear, hydration system and nutrition. That includes my primary stuff and backups. Fire suits, shoes, gloves, ear molds, helmets, head and neck restraints, and so on. When the race is over, I'm responsible for cleaning and sanitizing everything for the next race.

"When they tell me it's time to get to the race car, I will head out. And I will absolutely be following whatever direction they tell me to walk."

On Tuesday night, Tharp was in the Darlington Raceway infield helping to ensure that Johnson and everyone else is clear on where to walk. NASCAR and track operation officials have been laying down what feels like miles of red tape, marking off workspace borders for teams in the garage, walkways that connect those workspaces to the teams' big rig and even who can use which bathroom. Spotter spacing and parking spaces also are being marked.

Outside the racetrack, a medical screening area is being constructed where there normally would be hospitality tents and tailgaters. Everyone who arrives will be asked for their ID so the medical questionnaires they have previously filled out can be called up on a tablet computer by a medical professional. There, outside their vehicles, each person entering the track must appear on a roster turned in by their team, and then they will receive an on-the-spot medical screening.

And while there will not be COVID-19 testing as of yet, the possibility of future testing is on the table should the need arise. There is concern about someone who comes up symptomatic having passed it on to others. It happened in the F1 paddock during that same March weekend the Atlanta race was canceled. It happened last weekend in UFC. That's why the NASCAR contact logs will be kept. And it's yet another reason why the overall plan continues to be written in pencil. If there's an outbreak that starts to push toward a lack of control, the plug on the season can and will be pulled again.

"I relate it to my military days," said Tom Bryant, NASCAR's senior racing communications director, who has worked closely with Bobo on at-track logistics. Bryant served 20 years in the Army, including special operations and multiple tours of duty in Afghanistan. "You've done your mission brief, you've checked your weapons and you're waiting on the pickup -- and the 'what-ifs' start to race through your mind. You need to trust your team of people who have worked together to build this comprehensive plan that has been reviewed by a number of experts and trust that the talented people you work with will be able to perform.

"I'm not sleeping well, but I have a lot of faith in our team, and we have a very solid group of professionals who are ready to face things and make decisions."

Also located outside the track is a new "outfield medical center" set up in addition to the regular infield medical center, which will remain reserved for race-related medical situations (post-crash examinations, etc.). The outfield center is where anyone who shows any signs of illness will be sent for further examination.

Patrolling those areas -- as well as every parking lot and gate of Darlington Raceway -- will be dozens of law enforcement officers, from the Darlington County Sheriff's Office, South Carolina Highway Patrol and the South Carolina Law Enforcement Division, the state's investigative law enforcement agency. They will be on the lookout for anyone who tries to find their way into the racetrack or tries to turn Sunday's race into a protest opportunity or worse.

Darlington Raceway officials already have learned of large gatherings planned in the immediate area of the track, which they have politely worked to discourage. On Wednesday, a local man was arrested for calling the racetrack and leaving threatening messages, explained in the Darlington County Sheriff's arrest warrant as: "describing a possible explosive device and the results it may create to further his cause."

While the police presence might appear larger than normal, every other group will be much smaller. During a full race weekend that involves all three NASCAR national series -- Cup, Xfinity and Trucks -- there can be as many as 3,700 credentialed personnel in the racetrack infield, including competitors, NASCAR employees, track workers, support industry personnel and media members. On Sunday, that number will be less than 900.

The press box will have only four occupants, working as pool reporters for the media not in attendance. Motor Racing Network also will use a small team of radio personnel, made up only of those who live in the Carolinas and can make the drive. Fox will be working with a crew half the normal size to broadcast the race, utilizing only one reporter on pit road and moving production work such as replays and graphics to its studios in Charlotte. That's also where the broadcast booth will be, with Mike Joy and Jeff Gordon watching on monitors from separate studios, as they have throughout the network's broadcasting of iRacing over the past two months.

A captive TV audience

It would be naive to believe that the surprising success of eNASCAR broadcasts (roughly 1 million viewers per week) hasn't fed into NASCAR's desire to get back to the live track as soon as possible. Phelps has never disputed that. Much of the motivation behind all of the phone conversations, the politics, the education on pandemics and the laying out of the rules that will be so heavily enforced at Darlington and Charlotte has been to be the only live sport on television on Sunday afternoons for the foreseeable future.

If one were to receive a commission for every time the name of the 1979 Daytona 500 has been invoked over the past few weeks, he or she would not have to go back to work. That's when CBS aired its first live, flag-to-flag coverage of NASCAR's biggest race, on a Sunday when nothing else was on and much of the East Coast was socked in by a snowstorm. Those people stuck in their homes were gifted with perhaps the greatest finish in the history of motorsports, when Richard Petty held off Darrell Waltrip and A.J. Foyt, as Cale Yarborough had a fistfight with the Alabama Gang after crashing out of the lead on the final lap. NASCAR's three decades of growth started that day.

These days, it has been stuck in neutral. But now, so is the American sports-viewing public. Check that ... so is the entirety of sports, period. They will all be watching on Sunday to see if the road back to normal does indeed run through Darlington, South Carolina.

"I have no idea how it's going to feel when the green flag finally waves because this has been so different getting there," Knaus said. "I really hope that when we get some laps in, we have settled in, and it'll be like, 'OK, this feels normal.' If it does, it'll be the first time something has felt normal in a really long time. And that's really all anyone wants right now, isn't it?"

Tharp agreed.

"I've heard from a lot of people who work in a lot of different sports," said Tharp, who before joining NASCAR spent 20 years as the media relations director for the South Carolina Gamecocks, working with the likes of Lou Holtz and Steve Spurrier. "They all want to see if all of this we are doing to make this race happen works. They are all hoping that it does.

"We make this work, and we will, then sports are back. And other sports can hopefully take what we learn from this and they can get back soon too."

ESPN feature producer Tracy Wholf contributed to this report.