WEST SACRAMENTO, Calif. >> The good news for the Twins is that they haven’t lost their ace Pablo López for the entire season. The bad news is that they’ve lost him for much of it.

After leaving Tuesday’s game early, magnetic resonance imaging taken on Wednesday in California confirmed a Grade 2 teres major strain. The Twins said in a release that they expect López to be out for approximately eight to 12 weeks and the earliest he would begin a throwing program would be in a month.

It’s a crushing diagnosis for López, who was off to a strong start this season with a 2.82 earned-run average through his first 11 games of the season. López said he first felt something during the fifth inning of Tuesday’s game against the Athletics. He ended up throwing six more pitches after that and then came back out the next inning to warm up before gesturing for a team trainer and ultimately departing the game.

He was initially heartened on Tuesday by the fact that the injury did not appear to be his posterior cuff and that he never felt “a big pop.” But Wednesday’s medical image revealed a serious injury to the teres major, a muscle that attaches to the scapula.

Fellow starter Joe Ryan suffered the same injury last season. Ryan left an Aug. 7 game with the injury and did not return before the season ended.

Festa returns

With López heading to the injured list, David Festa has arrived in Sacramento to take his spot in the rotation.

The right-hander went to sleep on Tuesday night with the intention of being well-rested for his start Wednesday night for the Triple-A St. Paul Saints. And, apparently, he slept so soundly that not even 45 phone calls from six or seven different people within the Twins organization trying to reach him could wake him. Festa wasn’t woken from his slumber until some time in the 8 o’clock hour when director of player development Drew MacPhail banged on his apartment door.

“I figured my car was parked illegally or something,” Festa said of the door knocking. “But it was Drew.”

MacPhail had some good news for him personally — he was headed back to the big leagues and had a flight to Sacramento in just a couple hours. As of Wednesday afternoon, Festa was still on the taxi squad and the Twins had not announced their intentions for when he might start, though it appears likely to be Thursday.

For Festa, it’s another opportunity to prove to the Twins what he can do after a good three-start performance in the big leagues earlier this year when López was out with a hamstring strain. In those April starts, Festa gave up three earned runs across 13 innings pitched.

He then returned to the minor leagues and dealt with some inflammation in what he called his bicep/shoulder area, forcing him to miss a couple starts.

“It wasn’t something I wanted to do, but I knew it was the smarter way to go about it just so it didn’t become a longer issue,” Festa said. “The training staff did a great job down there of getting me back as soon as possible. My last two outings, I’ve felt good.”

And the results have been good, too.

He’s been throwing the sinker, that he started working on this winter, a lot more and is pleased with the feel he has for the pitch and how it has progressed. And now, he’ll have a chance to see it against major league hitters.

“Obviously, I’m bummed for Pablo,” he said. “I thought I’ve been doing a pretty good job my last few outings and I’m looking forward to build off that.

Correa scratched

About an hour and a half before Wednesday’s game was scheduled to start, the Twins officially announced that shortstop Carlos Correa was scratched with back tightness. He was replaced in the lineup by Brooks Lee.

Correa is often doing maintenance to avoid injuries in his back. He has a history of back issues, twice landing on the IL for it, though the last time that happened was in 2019 when he was still with the Houston Astros.

Briefly

Matt Wallner was not in the starting lineup for the second straight day because of the opposing lefty the Twins were facing. Notably, fellow lefty Trevor Larnach started both of those games and manager Rocco Baldelli praised how Larnach has looked in his at-bats against southpaws. “He’s earning the opportunities because he’s looked that good,” Baldelli said. … Infielder Tanner Schobel, the Twins’ second-round pick in 2022, was promoted to Triple-A on Wednesday after slashing .292./.372/.465 in 49 games at Double-A Wichita this year.