The NBA is going to need to build a bubble.

The top challenge facing the league is creating a safe environment for players, coaches, referees, support staff and technical operators. An environment that, in the early stages of resuming the season, might not include fans. It might not include travel. It might not even include an arena.

Along with much of the sports world, the NBA has been watching the Chinese Basketball Association. There is optimism in China. There is progress. But the CBA's struggles to build a coronavirus-safe space to finish out the season foreshadows how difficult resuming play for the NBA will be when the COVID-19 pandemic slows enough to consider such measures.

Chinese players and coaches have been in limbo since Jan. 24, when the CBA shut down during the scheduled Lunar New Year break. Discussions about bringing the league back began as early as mid-February. But the uncertainty about the spread of the coronavirus has clouded the ability to effectively strategize the restart.

The season was supposed to resume the first week of April, then it moved to April 15. Now the CBA restart has been delayed to late April or early May, sources said. That could mean a layoff of more than three months since the league shuttered.

Teams called foreign players back this past week -- more than a dozen Americans, including Jeremy Lin and Lance Stephenson, have returned -- and had them enter quarantine for 14 days to ensure that they are healthy and cleared to play in time for a training camp.

The CBA has watched as basketball leagues in Japan and South Korea have attempted returns and canceled them. The CBA knows the eyes of the sporting world are on it and is cognizant of the stakes if there's a setback, sources said.

The Chinese government is also concerned about a coronavirus resurgence and announced plans to close the borders to foreign nationals starting March 28 after a new set of cases was detected from foreigners arriving in the country.

The CBA hasn't formally announced a plan, but multiple sources said that what has been drawn up includes clustering teams in one or two cities and playing one another in a round-robin format in empty arenas over several weeks. There are 16 games left for each of the 20 teams in the league. The goal has been to play out the remaining schedule in full before moving on to the playoffs, with the hope that fans could eventually be admitted.

The CBA has discussed playing in Dongguan, a city in the warmer southern region that hasn't seen the same volume of cases as other areas. Another option has been Qingdao, a coastal city in northeast China that typically receives many travelers from nearby Japan and South Korea and has developed effective quarantine strategies. Teams would live and play in a constantly monitored environment, with players' temperatures checked several times a day.

If the plan were to unfold without incident, it could be a strategy the NBA considers among other options. Ideally, NBA teams would be able to train in their facilities and play in their arenas. But in the near term, that might be impossible, especially with escalating health concerns gripping the nation. The NBA could look at venues in a centralized location, perhaps playing in non-NBA cities.

Various ideas have been floated by players and executives. One is to consider using a sprawling casino property in Las Vegas, where everything could be held under one roof. Others have suggested playing in the Bahamas, where a ballroom could be converted into a playing court specifically for broadcast. There has even been talk of taking over a college campus in the Midwest, where reported cases of COVID-19 are lower for the moment.

Whatever the location, it would be a place where teams could sleep, train, eat and, hopefully, be kept healthy enough to have confidence in resuming play -- maybe not to finish out the season but to at least get restarted.

But as the repeated false starts and delays in Asia have shown, this is a massive challenge. When the idea of being quarantined in a hotel with other teams to resume play was presented on the Road Trippin' podcast this week, LeBron James said, "I ain't going for that s---. I'm not going for that."

He also reiterated that he didn't want to play without fans in the building but would do so if that's what it took to get back to the floor. Such concessions may be necessary if James wants a shot at playing for a championship this year.

There's no handbook on how to handle a global pandemic for sports leagues. This week, Dallas Mavericks owner Mark Cuban speculated that the league could be playing again by mid-May.

But in China, projections for return dates have come and gone many times. It turns out bubble-building can be hard.

ESPN DAILY: Pro basketball's return to China