Boof to Boston.

When the Twins opted to move forward with Carl Pavano in the starting rotation, it was evident that personnel numbers would be trimmed to accommodate him. After attempting to sign right-handed pitcher Boof Bonser to a very reasonable one-year, $550,000 contract - a deal that Bonser ultimately turned down – the Twins were forced to find a potential suitor or risk losing him for nothing. On Thursday, they found that suitor in the Boston Red Sox. Is this a great bargain or a buyer beware situation for the Sox?

There is plenty of evidence that the Sox are getting a decent product at a sub-prime cost. In 2008, Bonser ran into a considerable amount of hard luck. His .342 BABIP was inflated by a large number of groundball hits, his fielding independent metric of 4.19 revealed that he was pitching better than his ERA and his strand rate was at an inhumanly low 57.0 percent – all signs that Bonser is capable of pitching at a much higher level. The Red Sox are a team that builds their bullpen at a low-cost with guys that have a good stuff (Ramon Ramirez, Takashi Saito) and can be a cog in the late-innings machine. This, combined with his striking out 23.3 percent of hitters faced as a reliever in ’08, was enough to convince Epstein and Company that Bonser was a worthy risk.

The nature of Bonser’s injury would have been a concern to the Twins. After undergoing the same rotator cuff/labrum repair procedure in February 2009 as Jesse Crain did in 2008, it was obvious in Crain’s case that a pitcher does not hit the ground running the following season. It took Crain nearly 16 months to get back into his pre-injury form. This timetable for return, according to Will Carroll’s Saving the Pitcher, is the typical turnaround for these types of surgeries. With a crowded bullpen and an even more crowded payroll, there just was not space for someone that has a strong potential of being less than 100 percent healthy in 2010.

In addition to the health concern, Bonser has not quite demonstrated that he can be an effective reliever. While he’s got the minor league track record (917 strikeouts in 886.1 innings) and a decent cache of pitches (reviewed here last January) could translate into a solid bullpen member, there were also red flags about his numbers that suggested he might have work to do before getting to that status.  For starters, his record against left-handed batters is abhorred. As I noted a year ago, Bonser’s struggles against southpawed hitters did not manifest itself until his sophomore season in 2007 when they hit .349/.407/.563 with 16 home runs in the small sampling of 411 matchups. Those numbers continued into ’08 when they hit .315/.378/.489 with 8 home runs in 243 matchups. Fixing this issue would require attention both in game management (ensuring he faces fewer left-handed hitters) and developing an assortment of pitches that would combat his lefty opponents. As far as I can tell, it is the former that the Twins have larger issues with. Unlike the Red Sox who appear to structure their bullpen to handle various problems, the Twins tend to favor the workhorse relievers that can face both sides regularly when called upon.

As the Red Sox acclimate themselves with their newest arm acquired at below-market rate, Twins fans will look to see what sort of prospect they were able to gain from a deep Red Sox organization. It could eventually turn into a Jason Bartlett/Alexi Casilla-type that contributes at the major league level or a Zach Ward that does not pan out in Minnesota. To be sure, Bonser has the potential to succeed in a Red Sox uniform, provided that they exercise caution with his platoon splits, while the switch to Fenway Park should help alleviate the pounding that left-handed sticks usually apply.  At the same time, Bonser is capable of never rising up to his minor league expectations and being more trouble than he is worth in the process.