Righthander P.J. Walters was on the mound for about 10 minutes Wednesday, but enough happened during that time to send the Twins to a 9-8 loss to the Phillies and throw the starting rotation into more of a flux than it already was in.

Walters was able to throw 15 pitches -- only one reached 87 miles per hour -- before being pulled from the game because of right shoulder stiffness. You knew something was wrong when Twins manager Ron Gardenhire went to the mound to talk to Walters instead of pitching coach Rick Anderson, and that was confirmed when Twins trainer Dave Pruemer soon jogged to the mound.

"I thought the first three pitches were three straight changeups," Gardenhire said.

Walters tried to talk his way into staying in the game.

"He said, 'Skip, I'm fine. I can do this.'" Gardenhire said. "He was trying to protect the bullpen, that's what came out. He finally told me he had a sore shoulder, but no one knew about it. He hadn't said anything. Obviously, he was trying to pitch through something but that's not a good way to go about it tonight because it put us in a pretty big hole."

Walters said he's never had a problem getting loose before. He will have an MRI exam on Thursday. They already plan to recall righthander Lester Oliveros from Class AAA Rochester in time for Thursday's game. They just don't know who will be moved off the active roster to make room for him.

The other issue is the starting rotation. Liam Hendriks is expected to be called up from Rochester this weekend to start. Now the Twins likely will need someone to step in for Walters. Gardenhire said the club will sort through it all on Thursday.

"I couldn't get warmed up in the bullpen," Walters said. "Obviously, I came out in the first inning and it showed. It's just one of those things where I was stiff and just couldn't get it going. Guys pitch all the time through stuff like that and today it just wasn't going to loosen up.

"I've never missed a start before. Obviously I don't think I'll be throwing in five days. Hopefully it's not a big deal."

It was the worst-case scenario for Walters, who tried to walk that fine line between battling through stiffness and hurting his team.

"You never want to leave the field like that," he said. "You always want to be healthy and help your team. And the last thing you want is for the bullpen to throw nine innings. And the offense puts up eight runs and we lose. It was about as bad as you could have drawn it up."

All four batters Walters faced scored, and the Phillies offense didn't stop there. John Mayberry Jr., who was 2-for-5 with four RBI, homered off Jeff Manship in the first inning. Jim Thome cleared the batter's eye behind the center field wall with Hunter Pence aboard in the fourth inning that was estimated at 466 feet, the third longest homer at Target Field.

It also ended up being the game-winning hit, something Thome did a few times with the Twins in 2010 and 2011.

"A man hit that ball," Gardenhire said of Thome, who was 2-for-4 with four RBI.

The Twins got home runs from Trevor Plouffe and Josh Willingham, then revved up the announced crowd of 32,581 with a four-run seventh inning to get them within 9-8. But the Twins ran out of answers against setup man Chad Qualls and closer Jonathan Papelbon.