MIAMI — Even if the Mets hit a speed bump and lose significant ground in the standings between now and the Aug. 1 nonwaiver trade deadline, it almost certainly wouldn’t be enough to make them into sellers, according to a person with knowledge of the team’s thinking.

Instead, with a soft September schedule, the second wild card and a preference to recoup draft picks with any departing free agents, the Mets would likely remain buyers in hopes of making up ground later in the season.

Second baseman Neil Walker would be a free agent at season’s end, as would Yoenis Cespedes, should he choose to exercise his opt-out clause as expected.

Both would be the most attractive trade pieces should the Mets sell. But the source said the Mets would rather make qualifying offers to Walker and Cespedes at season’s end, ensuring that they’d receive draft picks as compensation if they signed elsewhere.

Bartolo Colon is also a free agent and he drew interest from other teams in the offseason. But the Mets are inclined to keep him to help absorb innings later in the season.

The Mets remain in the market for a middle reliever.

The Mets are in the middle of a three-game series against the Marlins, who for now own the second wild card. On Monday night, the Cardinals come to Citi Field. Their hot streak has been enough to propel them to just a game back in the race for the second wild card, half a game ahead of the Mets entering Friday night.

The Cardinals, Mets and Pirates entered Friday night within three games of a playoff berth.

But the Mets have a major schedule advantage down the stretch, with 19 of their final 25 games against teams that are likely to finish with losing records.

Extra bases

Cespedes returned to the starting lineup as he continues to deal with a right quad that is not 100 percent. Terry Collins said that with carefully scripted off days, the goal is to keep the condition from worsening . . . Zack Wheeler threw a bullpen at Marlins Park. He’s close to facing batters, the next step in his rehab from Tommy John surgery.