The New York Mets traded veteran left-hander David Peterson to the Chicago Cubs for minor-league infielder Cole Mathis, the teams announced Thursday.
The move came after the Cubs swept a doubleheader from the Mets at Citi Field on Wednesday.
Peterson, a free agent after this season, was an All-Star with the Mets last summer but has struggled to recapture that form in 2026. He's bounced between the rotation and bullpen and owns a career-worst 6.09 ERA and 1.65 WHIP across 68 innings. However, the 30-year-old has shown some positive signs, with his 8.3 K/9 sitting a tick higher than in 2025.
Peterson will likely get the chance to be a full-time starter again in Chicago, as the Cubs' staff has been decimated by injuries this year. Ten pitchers are currently on the injured list, including starters Edward Cabrera, Justin Steele, and Jameson Taillon.
A first-round pick of the Mets in 2017, Peterson owns a lifetime 4.31 ERA, 3.91 FIP, and 1.40 WHIP with 677 strikeouts across 147 big-league appearances (123 starts), all in New York.
Right-hander Yosver Zulueta was designated for assignment to open a 40-man roster spot for Peterson. The Cubs also reinstated left-hander Matthew Boyd from the IL ahead of his start against the Mets on Thursday and optioned reliever Gavin Hollowell to Triple-A.
Mathis, 22, was ranked as the Cubs' No. 13 prospect by MLB.com. He's hitting .272/.396/.585 with 10 home runs and 39 RBIs across 182 combined plate appearances between Low-A Myrtle Beach and High-A South Bend this season.
While he has experience playing both corner infield spots, Mathis profiles as more of a first base/designated hitter type long term.
The trade could be the first of a summer-long sell-off for the Mets, who dropped to 12 games below .500 on Wednesday.
