The Chicago Cubs, desperate to bolster a starting rotation ravaged by injuries, agreed to acquire struggling New York Mets left-hander David Peterson in exchange for minor league infielder Cole Mathis on Wednesday night, sources told ESPN’s Jeff Passan, hours after completing a doubleheader sweep of the Mets at Citi Field.

Right-handers Edward Cabrera (hamstring) and Ben Brown (neck) became the latest Cubs starters to go on the injured list Wednesday, joining Justin Steele (elbow), Cade Horton (elbow), Jameson Taillon (hamstring) and Matthew Boyd (knee). Of the Cubs’ projected starters to open the season, only left-hander Shota Imanaga is on the active roster, though Boyd is slated to return from the IL to start Thursday’s series finale against the Mets.

In Peterson, the Cubs receive a veteran who has tumbled from All-Star to one of the worst starters in the majors since the second half of the 2025 season. Peterson, a ground ball specialist, owned a 2.83 ERA on Aug. 6 through 21 starts. Since then, he has a 6.98 ERA in 17 starts and eight relief appearances.

The Mets’ longest-tenured player, Peterson threw his final pitch for the franchise on Sunday, when he allowed five runs (four earned) over four innings in a 6-2 loss to the Philadelphia Phillies. It had been the 2017 first-round pick’s first start in nearly a month; the Mets had used an opener for Peterson in his previous four outings and were likely to use one for him again Friday against the Phillies.

His precipitous decline exacerbated the Mets’ rotation troubles. What had been considered a strength entering the season has become a calamity with a 4.97 starter ERA that ranks 28th in the majors. The problem has only intensified in June with a 6.78 ERA that ranks last, fueling the disappointing Mets’ fall to a season-high 12 games under .500 after giving up 50 runs over the past five games — all losses.

Chicago’s starters have not been much better this season with a 4.64 ERA that is 25th in the majors. But the Cubs, unlike the Mets, are in playoff contention, occupying the third NL wild-card spot, and will look to the 30-year-old Peterson to help navigate these turbulent waters after Cabrera was carted off the field Tuesday with a hamstring strain and Brown was sidelined after attempting to pitch through neck pain since June 13.

Peterson will likely slot into the rotation this weekend against the first-place Milwaukee Brewers, who have a seven-game lead on the Cubs and St. Louis Cardinals in the National League Central.

The Cubs drafted the 22-year-old Mathis in the second round of the 2024 draft. He batted .272 with 10 home runs and a .981 OPS in 39 games between the Cubs’ Low-A and High-A affiliates this season.