According to Ken Rosenthal of Fox Sports, the Red Sox have signed former Colorado Rockies starting pitcher, Aaron Cook, to a minor league deal with an invite to Spring Training. The agreement will be final pending a physical.
Primarily a sinkerball pitcher, Cook has an inate ability to induce a great deal of ground balls (55-60% GB%). Against the backdrop of an airtight defense, this skill is a major asset. In Boston, he’ll have two of the best defensive players on the right side of the infield in Adrian Gonzalez and Dustin Pedroia, which should greatly help him neutralize left-handed pull hitters like Mark Teixeira. This will be is especially true if he can consistently keep the ball low in the zone. The left side of the infield will be a different story as Marco Scutaro and Kevin Youkilis have average to below-average range. Still, it shouldn’t matter quite as much since Cook has been far more successful against righties (3.97 career FIP) than lefties (4.82); especially in recent seasons. Unless Cook is plagued by some bad luck on balls in play, the left-side defense shouldn’t be too much of a factor.
Like most pitchers who heavily rely on their sinker, Cook doesn’t generate a great deal of strikeouts (9.8%). He throws three pitches (curveball, slider, and four seamer) in addition to the sinker with some regularity, but only the curveball registers a double digit whiff rate (11.2%). Moving from the NL West to the AL East won’t likely help this matter as he’ll no longer be afforded the luxury of facing the pitcher two or three times a game. Additional contact increases the likelihood of giving up a hit, and more hits increases an opponent’s run potential. Once you factor in his 7.2% walk rate (which isn’t poor, but in comparison to a 9.8% K%, it’s not great) and his worse than league average HR/FB% (10.2%); we can probably expect his projected ERA to increase anywhere from 0.25 to 0.50 runs per game as a result.
While I have concerns about Cook’s ability to pitch effectively in the AL East with his criminally low strikeout numbers, that’s not really the point. He has a servicable arm with a decent track record (13.6 fWAR between 2006 and 2009), and gives the Red Sox some much needed rotation depth. Provided he can stay healthy and benefit from a little bit of good fortune defensively, he should be able to provide some value given the low risk his contract provides. If it turns out he’s not fit for the rotation, the Red Sox can either move him to the bullpen; send him to the minors as insurance; or release him outright at no real cost to the club.
The Cook signing certainly isn’t sexy, but these are the kinds of depth moves every contending team needs to make.