Baker, 31, pitched all or part of his seven big league seasons with the Minnesota Twins, the club that made him a second-round selection in the 2003 draft. But he pitched in only 23 games in 2011 and none last season after undergoing Tommy John surgery in April.
"I truly believe if you put the work in and prepare yourself for every start, that's the best you can do," Baker said. "Once you go out there and you are fully prepared then it's about executing pitches. If I can execute pitches then I can be a very productive pitcher and give this team a chance to win some ballgames. In saying that, I think we're going to have a lot of fun. I'm excited working with the coaching staff and medical staff.
"It's a big season for me and the organization. I look forward to giving the team a chance to win."
Cubs president of baseball operations Theo Epstein acknowledged the risk in signing a pitcher coming off Tommy John surgery
"The reality is that it's not exactly a buyer's market for pitching right now so you have to take your risks," Epstein said. "Do you want to take a risk on the guy with bad makeup? Do you want to take the risk on the guy with bad command? Or do you want to take a risk on a guy you really believe in who's coming off Tommy John surgery at an appropriate value point? I think we are very comfortable placing our bet on Scott Baker."
The Cubs had targeted the addition of at least two starting pitchers this offseason. They nearly traded for right-hander Dan Haren earlier this month, but that deal with the Los Angeles Angels, which would have included closer Carlos Marmol, fell apart and was abandoned.
In 2011, Baker posted a 2.86 ERA through the first three months before going on the disabled list with an elbow strain. He attempted a return late in the season, finishing the year with an 8-6 record and a 3.14 ERA.
Epstein said he expects Baker to be ready for the starting rotation.
"Obviously there are no certainties on rehabs, but we spent quite a bit of time on the medical and on the rehab, and it was described by our staff as an ideal Tommy John rehab so far," Epstein said. "Knock on wood. Everything has gone perfectly so far, and he has really attacked it in an ideal manner. He has been sort of very curious about the nature of the rehab, the nature of the surgery. He spent some time to figure out different things he can do to put himself in good position.
"He understands that a lot of Tommy John rehab is about your shoulder and getting your shoulder in as strong condition as possible. He's put the work in to get himself on an excellent timetable. He has every day plotted out from here to spring training. If things go perfectly he will be stretched out to about five or six innings by that first week of the season. We're going to use good judgment every step of the way. It's not important if it's Opening Day or 10 days into the season as it is that he comes back healthy."
Overall, Baker is 63-48 with a 4.15 ERA in 163 appearances, with all but four of those coming as a starter. He averaged 13 victories, 30 starts and a 4.11 ERA from 2008-10 and was the Twins' Opening Day starter in 2010.
The 6-foot-4, 215-pounder is fourth all-time in Twins history in win percentage at .568 (minimum 100 appearances), 11th in starts with 159, 11th in victories and 11th in strikeouts with 770.
Baker is a native of Shreveport, La., and attended Oklahoma State, where he was a second-team All-Big 12 selection in 2003.