The Twins' task of rebuilding their starting rotation grew even tougher Tuesday, when free agent Scott Baker signed a one-year, $5.5 million deal with the Chicago Cubs.

Baker, 31, who missed last season recovering from Tommy John ligament-replacement surgery on his right elbow, expressed interest in re-signing with the Twins. After they declined his $9.25 million option two weeks ago, he said the sides had made progress toward a new deal.

But the negotiations hit a snag, with the Twins determined to add a 2014 option to Baker's contract and the righthander hoping to re-establish his value with a one-year deal before hitting the free-agent market again next fall.

"I'd rather not get into that [description of the negotiations]," Twins General Manager Terry Ryan said. "It wasn't meant to be. He's a Cub now, so we wish him well."

A second-round pick out of Oklahoma State in 2003, Baker went 63-48 with a 4.15 ERA for the Twins over seven seasons. The Twins gave him a four-year, $15.25 million contract in March 2009, only to see him start that season on the disabled list because of shoulder stiffness.

He made his lone Opening Day start in 2010 and ranked with the American League leaders with a 2.86 ERA on July 28, 2011, before hurting his elbow.

Asked how much the Twins will miss Baker, Ryan said, "The thing is we haven't had him on the field much the past two years."

Baker tried returning this spring, but the elbow acted up again and on April 17, he had Tommy John surgery. He's reported no setbacks during his rehab and hopes to be throwing off a mound when pitchers and catchers report to spring training.

"I have every intention of being a competitive pitcher next year right away," Baker told reporters in a conference call.

After collecting $6.5 million from the Twins last year, he can earn up to $1.5 million in incentives from the Cubs, based on innings pitched, bringing the potential value of the deal to $7 million.

This is the second recent gamble the Cubs have taken on a pitcher coming back from Tommy John surgery. In July, they traded Paul Maholm to the Braves for Arodys Vizcaino, who had the surgery March 20.

"The reality is, it's not exactly a buyer's market for pitching, so you have to take your risks," Cubs President Theo Epstein told reporters. "Do you want to take a risk on a guy with bad makeup? Do you want to take a risk on a guy with bad command?

"Or do you want to take the risk on a guy you really believe in who is coming off Tommy John surgery and has appropriate value points? I think we're very comfortable placing our bet on Scott Baker."

Meanwhile, the Twins move forward with Scott Diamond as the only starter penciled into next year's rotation. Carl Pavano is another free agent who could leave this offseason.

Beyond Diamond, the Twins' in-house starting pitching candidates include Liam Hendriks, Cole De Vries, Brian Duensing, Kyle Gibson, Nick Blackburn, P.J. Walters and Esmerling Vasquez.

"We definitely need pitching," Ryan said. "We'll move on and keep looking at other options."