Chicago Cubs left-hander Matthew Boyd hurt his left meniscus while playing with his children at home on Wednesday morning and was placed on the 15-day injured list.

Cubs manager Craig Counsell said that Boyd had an MRI that revealed the knee injury and the pitcher will require surgery. The move was retroactive to Monday.

"It's kind of unexplainable," Counsell said. "Kind of an innocent, going down to the ground and getting back up.

"He woke up this morning a healthy player," the manager added. "He's just trying to process it and get all the information from the doctors to figure out what's next."

Counsell said the timetable for Boyd's return will be determined after the surgery, but the team expects him to play again this season.

Boyd, 35, was on the IL from April 2-21 because of a left biceps strain. He is 2-1 with a 6.00 ERA, six walks and 31 strikeouts in 24 innings over five starts this season.

An All-Star for Chicago in 2025, Boyd is 62-78 with a 4.61 ERA in 218 career appearances (204) starts for the Toronto Blue Jays (2015), Detroit Tigers (2015-21, 2023), Seattle Mariners (2022), Cleveland Guardians (2024) and Cubs.

In a corresponding move, Chicago selected the contract of right-handed reliever Trent Thornton from Triple-A Iowa. They also designated lefty Charlie Barnes for assignment to clear room on the 40-man roster for Thornton. Righty Yacksel Rios was sent outright to Iowa.

Thornton, 32, is 0-0 with a 3.18 ERA in 5 2/3 innings over four games (one start) with Iowa this season. He has a career record of 14-19 with a 4.38 in seven seasons for the Toronto Blue Jays (2019-23) and Seattle Mariners (2023-25).

The Cubs already have starting pitchers Justin Steele (left elbow) and Cade Horton (right elbow) on the injured list.