MINNEAPOLIS -- The Twins were slated to play not one, but two division race-defining games on Friday. And ahead of arguably their most important games of the regular season to this point, they took not one, but two potentially season-defining injury blows.

Top-end starter Joe Ryan -- key to a potential playoff rotation -- is lost for a substantial period with a Grade 2 right teres major strain, and it’s unclear at this point if he’ll pitch again this season. And setup man Brock Stewart -- key to a potential playoff bullpen -- is lost for the year, set to undergo season-ending arthroscopic shoulder surgery on Tuesday.

That’s not to mention No 2. prospect and interim starting shortstop Brooks Lee also heading to the IL on Friday with a flare-up of his recent right shoulder issues, officially termed biceps tendinitis.

It’s about as suboptimal of a way imaginable for the Twins to start such a crucial day, but it’s the hand they’ve been dealt.

“It’s part of the game,” manager Rocco Baldelli said. “We have to find a way and adapt and bring in guys to get the job done. We have other guys on the mend who are also coming back and working their way back, too, so you kind of give and take a little bit. It’s unfortunate. It’s tough, but we have games to play and we have games to win.”

The news was particularly jarring amid the greater backdrop of the Twins’ inactivity at the July 30 Trade Deadline, when they were unable to find fits on substantial deals to bolster their pitching staff and emerged from the fray with only reliever Trevor Richards to add to the middle innings of their bullpen.

“There weren't as many paths as it appears there might be,” president of baseball operations Derek Falvey said. “You never know Joe Ryan is going to get hurt in the week following the Deadline. Those are unfortunate circumstances. We weren't going to be able to replace a Joe Ryan-type pitcher at the Deadline, for sure. It felt like for us we didn't really have those types of paths in the way that I would have hoped at the time.”

Still, that does make it tougher, Pablo López said.

“It does. There's no other way to say it,” López said. “You're never going to be able to account for things like this. You're never going to be like, ‘We're going to make a trade because someone is going to go down,’ or, ‘We're not going to make a trade because everyone is going to stay healthy.’ Obviously, hindsight is easier than foresight. It definitely makes it a little tougher.”

The immediate impact of these injury developments is that the Twins will now need to rely on unproven youngsters for three of their rotation spots, with rookies Simeon Woods Richardson and David Festa likely needing to step into more prominent roles, and Louie Varland and the yet-to-debut Zebby Matthews -- the club's second-best pitching prospect -- likely slated for meaningful starting innings.

In that sense, things could be worse, considering all four of those youngsters are (or were) highly regarded top pitching prospects -- but that’s about it for the depth until a possible return for Chris Paddack, who has had no issues in his recovery from a forearm strain and could soon begin a throwing program, Falvey said.

This is the risk the Twins had assumed with their inability to find a deal at the Deadline.

“We tried,” Carlos Correa said. “We really tried to make those trades. Just some teams happened to overpay for some players, and that's OK. That's going to happen.”

“We’ve been throwing young arms in our rotation all year long,” Baldelli said. “At times, it’s been one. Then, it was two. And now, it will be three. But you never know what’s coming around; you just don’t know.”

The Twins had expressed some optimism about Ryan’s condition after he removed himself from the third inning of Wednesday’s finale against the Cubs with what was originally diagnosed as a triceps strain, but imaging revealed the teres major strain that Baldelli said is expected to keep Ryan out for “weeks to months,” with less than two months remaining in the season.

“That’s basically what I left the conversation [after his outing] with: He doesn’t feel good, but probably could be worse,” Baldelli said. “That’s the way we talk, and that’s the way it went. [Then] the results of the MRI showed that it’s a very legitimate issue that he’s dealing with.”

As for Stewart, who was one of the linchpins of the Twins’ late-inning picture alongside Jorge Alcala, Griffin Jax and Jhoan Duran, the right-hander said the pain hadn’t really gone away in late July after he returned from a three-month absence for a right shoulder strain.

Though he admitted he’d almost been in denial for some time, Stewart said he opted for the surgery over another cortisone injection or a stem cell injection, with the arthroscopic procedure carrying a 5-6 month recovery that he hopes will have him ready for next Spring Training.

“Obviously pissed, frustrated, all those emotions,” Stewart said. “I wish this season went differently. I wish I was helping out way more. But also, kind of relieved to know that it's going to be fixed and I have a clean slate for next season.”