Four days after the Twins lost Pablo López to a shoulder injury that will sideline him for the next two months, they lost another starting pitcher.

Zebby Matthews was placed on the 15-day injured list Sunday with a right shoulder strain. There was no immediate timetable for his return, but he underwent an MRI exam Saturday morning that showed a moderate muscle strain, and he will be shut down from throwing for at least two weeks.

Matthews started feeling a little discomfort in his shoulder during a bullpen session in Tampa Bay nearly two weeks ago. He made two starts afterward, yielding five runs in 12 innings (3.75 ERA) with 11 strikeouts, before he began "feeling it a little more."

"It's not something we're too concerned with," Matthews said. "It seems to be something we can respond to, hopefully, pretty quick. We're hoping the time on the IL is short lived. … It's mainly during the last part of the throw is when I feel it. Everything else, it feels pretty good. We're just trying to get it to loosen up and get back to feeling normal."

The Twins activated lefty reliever Danny Coulombe from the injured list before Sunday's game, and Simeon Woods Richardson is expected to fill Matthews' spot in the starting rotation.

It's Matthews' first time on the IL in his professional career, since the Twins picked him in the eighth round of the 2022 MLB amateur draft.

"In the outing in Sacramento, Zebby had some minor soreness," Twins manager Rocco Baldelli said. "He wanted to stay in the game. It wasn't something that we were going to immediately take him out of the game for. That also happens a number of times over the course of a season.

"But as we got into the week, after his outing, and he's out there moving around, playing catch, getting assessed in the training room, we realized it was maybe more than just a peripheral issue or a small issue he could pitch through."

Woods Richardson, who was scratched from a scheduled start with the Class AAA St. Paul Saints on Sunday, is lined up to start Tuesday's series opener against the Texas Rangers. In three minor league starts after a demotion from the rotation, Woods Richardson gave up 15 hits and eight runs in 17 innings (4.24 ERA) while striking out 19 and walking four.

"[Matthews] is going to be down for a little while," Baldelli said. "We're going to have to just keep moving and bringing guys up and challenging guys the way we have."

The Twins don't have any proven starting pitching depth behind their current group — Joe Ryan, Bailey Ober, Chris Paddack, David Festa and Woods Richardson — putting pressure on each of them to remain effective. The Twins crumbled at the end of last season after injuries to Ryan and Paddack.

"It's tough," Matthews said. "We just lost Pablo there and then for me to go on the IL, too, it's definitely tough. I was feeling good out there, but it's a great time for somebody else to step up and help the team in the ways that they can, so I'm excited for that."