NEW YORK -- In a surprise development, Scott Baker underwent Tommy John surgery on his right elbow in New York, the Twins announced during Tuesday night's game against the Yankees.

Baker was originally scheduled to have season-ending surgery to clean up scar tissue on his flexor pronator tendon on Tuesday, but Dr. David Altchek decided that Baker also needed to have his ulnar collateral ligament repaired.

"It happens more often than you think, when someone has something and you go in and all the sudden it's a little different than you expected," Twins general manager Terry Ryan said. "And that is the case here."

Ryan said the recovery time will be 12-plus months, so there remains a possibility Baker won't be ready in time for the start of the 2013 season. Baker was originally scheduled to need six months of rehab before the decision was made to repair his UCL.

Ryan said that the two MRI exams taken on Baker leading up to the surgery didn't show a torn UCL, but that there was a possibility he would need the operation after examining the ligament following cleaning out the scar tissue in the tendon.

Baker, though, caused confusion during his news conference at Target Field last Wednesday, as he told reporters that the ligament looked great. But Ryan said there was a reason why the surgery wasn't simply arthroscopic.

"I do remember that, and I was a little less optimistic," Ryan said about Baker's comments. "When you don't scope something that means they're concerned, and they didn't scope it. That's why they went in, just in case they needed to repair it -- and that's what happened."

There's no guarantee Baker will be back with the Twins, as the club holds a $9.25 million option for next year. It's unlikely the Twins will exercise the option, but there's a chance the club could re-sign him at a discounted price.

Morneau sits vs. CC, but eager to return to first

NEW YORK -- A day after playing first base for the first time this season, Justin Morneau said he felt just fine on Tuesday.

Morneau, though, was held out of the lineup against the Yankees because of his struggles against CC Sabathia, as he's a career .140 hitter (6-for-40) against the left-hander. Luke Hughes made his first start of the season at first base in his place.

Morneau said he plans on gradually playing more first base as the season goes along to ease back into being the club's regular first baseman.

"I don't know what the schedule is," Morneau said. "It's not going to be here on out the rest of the way. Hopefully this is the first step to being back out there every day or almost every day. The ultimate goal is always to be healthy enough to play every day. However many days over there, I'm not sure, but hopefully it's more over there than DHing."

Morneau went 2-for-5 with a homer in the Twins' 7-3 win, and said he felt more comfortable at the plate because he was able to keep busy in between at-bats by being out in the field.

"I felt like I was more into the game and more involved," Morneau said. "When you're out running the bases, it kind of helps. I got on base the first at-bat and it helps you feel involved in the game. I don't know whether or not that made a difference but I didn't have as much time to think about those things, which is good."

Morneau also said he didn't feel any ill effects after diving for a ball at first base in the seventh inning. It was a diving play at first that ended his season last year on Aug. 28, as it re-aggravated his concussion-like symptoms.

"It was just a natural reaction to see how I felt after that, but everything reacted really well," Morneau said. "I felt good. But it was a different play. The ball kind of took a more predictable hop. I just about got it. It was more of a reaction play. It's part of the game. I didn't really think about it until after, which was good."

Perkins may rejoin Twins on Wednesday

NEW YORK -- Twins reliever Glen Perkins' left forearm felt better on Tuesday, and if all goes well after meeting with team physician Dr. Dan Buss early Wednesday, Perkins could rejoin the team in New York in time for Wednesday's game.

Perkins, who allowed three runs without recording an out on Sunday, stayed back in Minnesota to undergo an MRI exam on his forearm on Monday, which showed only inflammation in his left forearm.

"Perkins is doing better," Twins general manager Terry Ryan said. "It's going to be an early-morning decision on whether he flies and joins us."

Perkins, though, remains a candidate to be placed on the disabled list if he's not ready to go, as the Twins plan to recall right-hander Jason Marquis from Double-A New Britain to start Wednesday's game against the Yankees.

Another candidate to be placed on the disabled list is right-hander Nick Blackburn, who is missing his scheduled start on Thursday because of stiffness in his right shoulder. Blackburn is slated to throw bullpens on Friday and Sunday with the hope of returning to the rotation on Tuesday.