Matthew Boyd underwent successful surgery on his left meniscus, the Chicago Cubs announced Thursday, after the left-hander suffered the injury playing with his children.

The Cubs did not offer a timeline for Boyd’s return, though they expect the pitcher to miss at least a month.

“It’s minor meniscus surgery,” Cubs manager Craig Counsell said. “We know he’s going to miss a month or six weeks. Probably closer to six weeks for him to ramp back up.”

“The biggest thing is how much time do we miss throwing? The knee is going to recover quickly, but how much throwing downtime do we have to take.”

Boyd, who made 31 starts in 2025 and participated in the World Baseball Classic during spring training, will go on the 15-day injured list for the second time this season. He is 2-1 with a 6.00 ERA in five games this season.

Boyd will join top-end starters Justin Steele (elbow) and Cade Horton (elbow) on the injured list. Steele is expected back later this summer, but Horton is out until next year.

On Wednesday, Counsell stopped short of naming right-hander Javier Assad as Boyd’s replacement. The team has “loose” plans for Boyd’s next start, which comes Friday against the Texas Rangers.

The Cubs have overcome their pitching injuries so far this season thanks to a deep offense, which ranks third in scoring at 5.4 runs per game. They have won eight in a row and 18 of 21 games overall after beating the Cincinnati Reds 7-6 on Wednesday night.

Corbin Martin, who gave up three runs without recording an out in the ninth inning Wednesday, was designated for assignment.