The Twins officially announced the move Thursday morning after Pelfrey passed his physical.
Pelfrey, 28, had a strong start to the 2012 season with a 2.29 ERA in three starts with the Mets before undergoing season-ending Tommy John surgery on his right elbow May 1. He was non-tendered by the Mets after the season, making him a free agent, but he's expected to be healthy by Opening Day, according to Twins general manager Terry Ryan.
"We like the guy's stuff," Ryan said. "We like his makeup. We think he fits in here well. We brought him on certainly to be one of our starters."
The 6-foot-7, 250-pounder has a career 50-54 record with a 4.36 ERA, 506 strikeouts and 318 walks over 896 1/3 innings, all with the Mets.
The sinkerballer's best seasons were in '08, when he had a 3.72 ERA in 200 2/3 innings, and in '10 when he had a 3.66 ERA in 204 innings. His last full season came in '11, when he had a 4.74 ERA in 193 2/3 innings. But Ryan said he remains hopeful Pelfrey can return to his form from '10.
"He throws hard," Ryan said. "He's got pitches. Going back, he didn't pitch this year except for about two or three starts. He was off to a pretty good start, but unfortunately it wasn't meant to be because of Tommy John. The previous year he had a down year. But he does give you innings and gives you starts. He's only 28. So we're hoping we're reverting to 2010, when he had a very good year with the Mets."
Before undergoing Tommy John surgery, Pelfrey proved to be durable, throwing more than 180 innings in four straight seasons. He's regarded as a ground-ball pitcher and keeps the ball in the ballpark, which should help a staff that gave up the second-most homers in baseball last season despite playing at spacious Target Field.
"I really believe this ballpark is suited to what he can do," Ryan said. "I don't refer to that too much, because the Mets ballpark in 2011 was similar to this one. So I'm not going to pretend like the ballpark will be the cure-all for everything, but we do like his stuff."
Pelfrey is expected to join a Twins rotation that includes Scott Diamond, Vance Worley and Kevin Correia. Prospect Kyle Gibson, who is also coming off Tommy John surgery, is another candidate to start the season in the rotation.
But the Twins will be more cautious with Gibson because he hasn't thrown as many innings as Pelfrey.
"He'll be a little different than Gibson because he's hit that 200 mark a few times in his career," Ryan said. "He's pitched at least 180 innings quite a few times."
Ryan added that he might not be done adding starting pitching, as the Twins are still on the lookout to improve a rotation that finished with the second-worst ERA in the Majors last season.
"I think we have to continue to look," Ryan said. "Whether we secure another guy or two, I'm not positive, but we certainly have to continue to look."