With free agency underway, the offseason is going to pick up steam. What are the big questions facing all 30 teams?

Here's a look at the NL East, which features four potential contenders, including the World Series champs.

NL Central team-by-team previews

Atlanta Braves: Will Gerrit Cole, Madison Bumgarner or any other star pitcher be in a Braves uniform next season?

2019 record: 97-65
2020 World Series odds: 10-1

General manager Alex Anthopoulos was as patient as anyone last season as he methodically built a division winner -- not just in the winter but during the season as well. In fact, some of his best work came after April 1, including the acquisitions of Dallas Keuchel, Mark Melancon and Shane Greene. But it's a new year, and it might call for a new strategy.

With a dynamic offense in place, combined with young starters such as Max Fried and Mike Soroka, it's time for the Braves to put the finishing touches on their rotation. Keuchel was a nice stopgap, but the Braves came up short in the postseason in part because Keuchel pitched on short rest and Fried threw in four of the five games in the division series against the Cardinals. The Braves' needs this offseason scream "veteran, front-of-the-rotation guy," and there are some options on the free-agent market in Gerrit Cole, Madison Bumgarner and Stephen Strasburg. -- Jesse Rogers

Washington Nationals: What happens if the Nationals lose Stephen Strasburg and/or Anthony Rendon?

2019 record: 93-69
2020 World Series odds: 14-1

Beginning with what we know: The Nationals want to keep Stephen Strasburg and Anthony Rendon, two of their title-winning pillars. Their situations entering free agency were different. Strasburg chose to opt out of his contract, a decision that didn't feel like a foregone conclusion until his remarkable postseason run reached its apex. Rendon was headed to the open market all along after negotiations on an extension didn't connect. But Washington has the flexibility -- especially considering what you figure will be a post-title revenue boost -- to re-sign both stars and still have a little wiggle room under the luxury tax threshold to play with.

But if either or both depart, what's the pivot? Does GM Mike Rizzo pursue star-level players on multiyear deals to replace them? Or does he go for shorter-term solutions? And does he spread the payroll around to build depth in lieu of the lost star power?

Losing Strasburg creates the more urgent short-term problem since there simply aren't many starting pitchers at his level and the Nats lack internal options. One of the other elite hurlers -- Gerrit Cole -- is a free agent. Barring that unlikely pursuit, Rizzo could target a couple of next-tier starters on two- or three-year deals. After all, he still has Max Scherzer and Patrick Corbin to head up the starting staff. As for Rendon, losing him would be a bummer, of course, but Washington still has a young infield prospect ready to ascend in Carter Kieboom and could turn to a short-term third baseman -- Josh Donaldson? -- to help fill the void.

There are a lot of ways this offseason could play out for the champs. But the preferred path is the simplest: Strasburg and Rendon returning to defend the franchise's first title. -- Bradford Doolittle

New York Mets: Is Carlos Beltran the missing ingredient?

2019 record: 86-76
2020 World Series odds: 22-1

The Mets went 40-50 in the first half before finishing strong with a 46-26 record in the second half -- the second-best record in the National League after the break. In two seasons under Mickey Callaway, the Mets improved from 70 to 77 to 86 wins -- even though the moves his general manager made last offseason failed miserably (trading for Robinson Cano and Edwin Diaz, signing Jed Lowrie and Jeurys Familia). Maybe Callaway wasn't the answer as manager, but there isn't much evidence he was the problem, either. In other words: Maybe rookie manager Carlos Beltran will be the right guy at the right time, the next Alex Cora who comes in and wins a World Series in his first season.

More likely, the Mets will have to upgrade the roster. But will Brodie Van Wagenen be aggressive again this winter after last year's misfires? The four areas to address: 1. Who plays third base? This could be J.D. Davis, who was forced into left field last year (he's not a left fielder), or it could be Lowrie or even Cano; 2. Who plays center field? Juan Lagares is a free agent, so Brandon Nimmo is the only possibility on the current 40-man roster. An outfield of Michael Conforto, Nimmo and Jeff McNeil will work, with Yoenis Cespedes still hanging around if he's healthy; 3. How do you fix the bullpen? Realistically, the best option is for Diaz and Familia to simply pitch better; 4. Who replaces Zack Wheeler? You have Marcus Stroman for a full season but no strong candidate for the No. 5 starter (let alone depth after that).

Cot's Contracts says the Mets are just $20 million under the luxury tax threshold -- they have never gone over. As much as Mets fans might dream about signing Anthony Rendon, don't count on it. I'd suggest going after another starter, such as Hyun-Jin Ryu, and adding a bullpen piece while rolling the dice on Diaz. I suspect that whatever the Mets do will be more surprising than that. -- David Schoenfield

Philadelphia Phillies: How do you get this team above .500 and into the playoffs?

2019 record: 81-81
2020 World Series odds: 16-1

After a busy and expensive 2018-19 offseason that saw the Phillies add Bryce Harper, J.T. Realmuto, Jean Segura, Andrew McCutchen and David Robertson, the Phillies improved from 80 wins all the way to ... 81. It cost manager Gabe Kapler his job -- a second straight September fade was the final straw -- with Joe Girardi replacing him. The Phillies haven't finished above .500 since 2011. Only the Padres and Marlins have gone longer without a winning season. All those veterans are back, as well as the cast of starting pitchers who failed to improve in 2019 -- Zach Eflin, Vince Velasquez, Nick Pivetta. The Phillies were eighth in the NL in runs and 12th in runs allowed. What to do?

The payroll right now reads $155 million, with an estimated luxury tax total of $179 million (according to Cot's Contracts). That gives them about $28 million to spend to avoid going over the tax threshold, which they have never done. They could go after a premium free agent such as Anthony Rendon or Josh Donaldson to play third base instead of Maikel Franco (minus-0.8 WAR in 2019). Franco is probably a nontender candidate, which would save the Phillies another $5.5 million or so.

If more depth and the rotation are the priorities, they could go after a couple of second-tier free agents, say Mike Moustakas or Didi Gregorius to play third base, and a pitcher like Dallas Keuchel, Rick Porcello or Wade Miley. If they think prospect Alec Bohm is ready to take over at third -- he reached Double-A but might also be a first baseman -- maybe they pour everything into pitching and hope for better seasons at the plate from Realmuto, Segura and Rhys Hoskins and a healthy McCutchen. -- Schoenfield

Miami Marlins: Are the Marlins still in flip mode?

2019 record: 57-105
2020 World Series odds: 1,000-1

In February, the Marlins shipped All-Star catcher J.T. Realmuto to the Phillies, bringing back a new regular backstop in Jorge Alfaro and, among others, a top pitching prospect in Sixto Sanchez. That was arguably the last headline-grabbing veteran-for-prospects trade in Miami's current rebuild.

Smaller-scale deals followed during the season: Sergio Romo, sent to the Twins for Lewin Diaz; Trevor Richards and Nick Anderson, sent to Tampa Bay for Ryne Stanek and Jesus Sanchez. Miami still has to run out the clock on the last season of Wei-Yin Chen's contract, but given the lack of pre-Derek Jeter veterans remaining, one might think that the Marlins have exhausted their options for these kinds of trades.

Obviously, that can change by next season's deadline, as the Marlins fill in their 40-man roster this winter, but what about hot stove trades? Is there anything to be done in the trade market? The answer to that might reveal something about how lead exec Jeter and GM Michael Hill view their timeline. When you look at some of the most productive Marlins from last season -- Brian Anderson, Caleb Smith, Jarlin Garcia, Richards, Alfaro, etc. -- they are at those in-between ages (26, 27 years old) where you have to decide whether you're going to move into contention in time to capitalize on their remaining controllable seasons.

If the answer is no -- that Miami still needs a couple of more seasons of incubation -- moving some of the older controllable players sooner than later might make the most sense. Alas, it would also signal another 105-plus-loss season for a franchise that has barely cracked 800,000 in attendance in each of the past two seasons. Tough call. -- Doolittle