The Post’s Dan Martin breaks down the Mets’ NL East foes:

Atlanta Braves

2019: 97-65
Manager: Brian Snitker (fifth year)
Spring training site: North Port, Fla.

Key additions: The Braves didn’t really seem to need another outfielder, but they signed Marcell Ozuna, anyway. Cole Hamels arrived — and like Ozuna, on a one-year, $18 million deal — to bolster the rotation. Lefty Will Smith slides into the bullpen following two standout seasons with the Giants — joining Darren O’Day and Chris Martin, who were both brought back. Ex-Met Travis d’Arnaud, fresh off a bounce-back season with Tampa Bay, will be behind the plate.

Marcell Ozuna
Marcell OzunaPaul J. Bereswill

Key losses: Josh Donaldson declined a qualifying offer from Atlanta and signed a four-year deal with Minnesota, despite Atlanta’s attempt to keep him on a multi-year deal. Dallas Keuchel signed with the White Sox and Julio Teheran went to the Angels as a free agent.

Storylines to watch: The Braves will spend spring training in North Port after moving out of Disney last spring. Third base is an area of concern following the departure of Donaldson, with Johan Camargo or prospect Austin Riley competing for the job — unless they can swing a trade for either Nolan Arenado of the Rockies or Kris Bryant of the Cubs.

Philadelphia Phillies

2019: 81-81
Manager: Joe Girardi (first season)
Spring training site: Clearwater, Fla.

Key additions: The revamped Phillies have a decidedly New York look to them, with Girardi replacing Gabe Kapler as manager and Didi Gregorius and Zack Wheeler arriving as free agents.

Key losses: Cesar Hernandez, Maikel Franco are out from the infield and Corey Dickerson is gone from the outfield, while ex-Met left-hander Jason Vargas was not brought back.

Storylines to watch: Girardi had a long run of success in The Bronx and returns to the dugout after two seasons. He’ll take over a Phillies team coming off a disappointing 2019, when they finished .500 following the huge signing of Bryce Harper and trading for J.T. Realmuto.

The Mets will be seeing a lot of Didi Gregorius and Zack Wheeler this season.
The Mets will be seeing a lot of Didi Gregorius and Zack Wheeler this season.AP

Washington Nationals

2019: 93-69
Manager: Dave Martinez (third year)
Spring training site: West Palm Beach, Fla.

Key additions: The Nationals brought in a pair of veteran bats on the right side of the infield, with Eric Thames coming to play first and Starlin Castro at second. Right-hander Will Harris, excellent a year ago in Houston, comes into the bullpen. Their most significant free-agent signing was bringing back Stephen Strasburg to their star-studded rotation.

Key losses: Anthony Rendon led the Nationals in almost every offensive category last year as the third baseman helped lead them to their first World Series title, but he signed with the Angels.

Former Marlin and Yankee Starlin Castro signed with the Nationals during the offseason.
Former Marlin and Yankee Starlin Castro signed with the Nationals during the offseason.Getty Images

Storylines to watch: How do the Nationals overcome the loss of Rendon? They’ll need the 21-year-old Juan Soto to continue to develop into one of the best hitters in the majors, and they’ll watch top prospect Carter Kieboom, who made an 11-game cameo with Washington last year.

Miami Marlins

2019: 57-105
Manager: Don Mattingly (fifth season)
Spring training site: Jupiter, Fla.

Key additions: Coming off a 57-win season, the Derek Jeter-led Marlins added some solid veteran hitters to their lineup with Jonathan Villar, Corey Dickerson and Jesus Aguilar — as well as to their bench, in Matt Joyce and Francisco Cervelli. That should give the offense more pop. In the bullpen, they brought in Brandon Kintzler and Yimi Garcia.

Key losses: The Marlins’ four main departures on offense were all ex-Yankees: Starlin Castro, Neil Walker, Martin Prado and Curtis Granderson. Wei-Yin Chen, a colossal disappointment in the rotation, was released — despite still being owed $22 million, a departure for the thrifty Marlins.

Storylines to watch: If the Marlins don’t show marked improvement this season, it could lead to an awkward situation between a pair of Yankees legends, team CEO Jeter and manager Mattingly. Miami also has high hopes for 23-year-old second baseman Isan Diaz.