There are quite a few free agents that should be attractive to the Red Sox this off-season. Because of that, we'll take them one at a time, and profile those who Boston might be a match with. Just because they're covered here, though, doesn't mean they're endorsed: this is meant to be an exercise in finding out whether or not the players in question should be future Red Sox.
Zack Greinke, Anibal Sanchez, and Kyle Lohse might be the ones getting the attention this off-season, but that doesn't mean they are all there is to choose from for teams looking to upgrade their pitching. There are pitchers out there who have their own risks that keep from them out of the price range of that trio, but when it comes down to it, they might have less overall risk than that group.
That's where someone like Brandon McCarthy comes in. McCarthy has never thrown 200 innings in a season. His 2009 season was cut short by a stress fracture in his shoulder, and multiple re-aggravations of the injury kept him out of the majors for all of 2010, and held him to just 56 innings in the minors. After resurfacing with the Athletics in 2011, McCarthy still dealt with the aftermath of the stress fracture, but managed to toss 170 frames with a 121 ERA+, finally delivering on the potential that he had back as a prospect in the White Sox and Rangers systems.
Two separate stints on the disabled list for shoulder strains cut into his production once more, but when on the mound, McCarthy was great once more, posting a 123 ERA+ in 111 innings. He ended up missing the end of the season after taking a line drive to the head, an accident that ended up requiring surgery to fully fix. If not for that, McCarthy likely would have finished the season with an additional 25-30 innings. Not what you want, but not as bad as what his totals represent sans context.
Injuries are obviously an issue with McCarthy. The stress fracture has been problematic for years now, and while there was no re-aggravation in 2012, the same shoulder had plenty of issues to contend with. Signing him would likely result in Franklin Morales picking up some spot starts as an injury replacement, or maybe Chris Hernandez would be placed on the 40-man roster to see if he can do a tolerable impression of McCarthy's ground ball-centric approach.
When he's healthy, though, it's hard to complain about anything. Despite below-average punch out rates, McCarthy has struck out four times as many batters as he's walked over the last two years. He's not an extreme ground ball pitcher by any means, but he's oriented much more that way than he used to be, and that helps keep the homers down. A right-handed pitcher who tries to keep the ball on the ground, and can limit walks, is a great fit at Fenway, one of the better stadiums in the game for right-handed hitters. If he's limiting walks, the strikeout rate won't matter so much, especially since McCarthy has never had any significant problems with batting average on balls in play. Fenway is sure to raise it a bit, but Boston should have a very good defensive squad in 2013, helping to alleviate some of that.
As said, signing him is a major risk, though, one that requires depth. Boston has some of that worked out -- Morales, maybe Hernandez, maybe knuckler Steven Wright -- but more might be required for this to work out. Rubby De La Rosa should be in the mix, as he's already on the 40-man and will likely begin the year at Pawtucket. Maybe Allen Webster takes a step forward this year, and is ready for a stint by the time -- assuming it happens -- that McCarthy has some kind of shoulder issue. Another depth signing would be nice, though, to help shore up the defenses, as all that's been listed above is Morales -- a pitcher with his own history of shoulder issues -- and a whole bunch of question marks. The Red Sox do not need another back-end of the rotation that looks like 2011's thanks to multiple injuries.
There's injury risk in every pitcher, though, just some more than others, so there's no reason to back entirely away from McCarthy unless the market loses its mind. Boston has the financial resources to offer McCarthy, who hasn't pitched since taking that liner to the head, a quality base salary with incentives for innings, as well as a lucrative 2013 option. If the rest of the market decides to go fully guaranteed on a deal for 2013, Boston can easily match that, too. The key is going to be to make sure that there is depth in place to compensate for McCarthy's shoulder, as well as potential side-effects no one has been able to see yet from his head injury. There is already a lot in place, but in a theme that has fit this off-season, there's still the need for more.