How David Peterson's struggles could impact Mets' pitching plans Sunday

David Peterson has been having a rough time of late, putting the Mets in a potential bind if they need to win their final regular season game to reach the playoffs.

Sep 23, 2025; Chicago, Illinois, USA; New York Mets pitcher David Peterson (23) throws against the Chicago Cubs during the first inning at Wrigley Field. Mandatory Credit: David Banks-Imagn Images | David Banks-Imagn Images

The New York Mets earned one of their biggest wins of the season on Tuesday night with almost no contributions from David Peterson. After an All-Star performance in the first half, Peterson's nightmarish second half continued as he couldn't get out of the second inning against the Chicago Cubs, giving up five runs in just 1.1 innings of work.

David Peterson goes just an inning and a third tonight in Chicago.

He has a 12.54 ERA in his last five starts. pic.twitter.com/8XcuvbCDjz

— SNY Mets (@SNY_Mets) September 24, 2025

The Mets' bullpen saved the day, allowing just two runs the rest of the way to buy the offense time to come back. But Peterson's fall from grace has been a stunning part of the team's second-half swoon; the 30-year-old has an ERA of 12.54 in his last five starts and 8.42 in his last nine, which could be a sign he is tiring after easily setting a career high in innings pitched this season.

Read More: David Peterson's splits expose major New York Mets concern

After the game, manager Carlos Mendoza was non-committal to Peterson's role going forward, noting that he still feels the lefty can be a valuable contributor for them over the next five games, including in a potential bullpen capacity.

Carlos Mendoza discusses David Peterson's outing tonight vs. the Cubs and says "he could play a big role" for the Mets for the remaining 5 games, potentially pitching out of the bullpen pic.twitter.com/0Fp3dIHSao

— SNY (@SNYtv) September 24, 2025

David Peterson's Struggles Could Force A Tough Mets' Decision On Sunday

The good news for the Mets is that they won the game, which combined with Cincinnati's loss gave them control of the final National League Wild Card spot once again. The Mets lead both the Reds and Arizona Diamondbacks by one game with five to go, with a magic number of 5 to lock up a playoff spot since they don't have the tiebreaker against either team.

"We already feel it. The Postseason is here for those teams." - @TheMayorsOffice ⚡️#MLBCentral weighs in on the NL Wild Card race and how important each game is. pic.twitter.com/N5zujG2Lak

— MLB Network (@MLBNetwork) September 24, 2025

There is a realistic possibility that the Mets will need to win their final game of the regular season against the Miami Marlins to either get into the postseason or keep themselves alive if they are in a tie with either Arizona or Cincinnati on Sunday. The problem is that the starting pitcher lined up for that game is Peterson, who would be the only option on normal rest if the Mets stick with their strategy of piggybacking Clay Holmes and Sean Manaea on Saturday.

Nolan McLean is scheduled to start on Thursday, which is his normal day of rest and lines him up to pitch Game 1 of a potential Wild Card Series. Brandon Sproat would be on an extra day of rest on Friday in Miami and the same would be true of the piggyback tandem on Saturday, leaving Peterson on normal rest for Sunday.

The Marlins hammered Peterson the last time they saw him in New York, knocking him out in the third inning on August 30th while scoring eight runs off of him. Peterson hasn't demonstrated much progress since that game, so it would be hard to see the Mets turning to him with their season on the line.

While an ideal world would see the Mets wrap up a playoff spot before then, which would then just allow them to let Peterson start and absorb some innings ahead of the Wild Card Series, the team needs to have options if it needs the game. One such option would be to split up the piggybacking group of Holmes and Manaea, using one on Saturday and the other on Sunday as traditional starters, but it is unclear if the Mets want to mess with the success of that pairing right now.

Another option would be a potential bullpen game on Sunday, which could have Peterson work in a bulk capacity behind an opener to situate him better and take advantage of a portion of Miami's lineup that is more left-handed. Assuming the Mets get through the next two days in Chicago without weather disruptions, they could empty their bullpen on Sunday knowing they'd have a day off on Monday before the start of a Wild Card Series.

This scenario could have been avoided, however, if the Mets had let Jonah Tong (who started on Wednesday) pitch on regular rest on Tuesday and used Peterson on Wednesday, leaving Tong in line for a second start if the Mets needed the game. Tong likely would have been unavailable for a Wild Card Series in that circumstance, but the Mets probably should have done that to give themselves the best chance to make the postseason.