The Red Sox are calling up Aaron Cook, but haven't done it just yet, as he pitched three days ago and isn't ready to go. With Junichi Tazawa sent back to Pawtucket yesterday, that leaves the Red Sox one bullpen arm short of where they would like to be. Since Tazawa can't be recalled for another nine days -- unless he's replacing someone with an injury -- that leaves things to Clayton Mortensen, another Triple-A pitcher with an option remaining.
Mortensen was acquired by the Red Sox in the Marco Scutaro deal this past off-season. His numbers have historically been iffy, with few strikeouts, an average walk rate, and a high reliance on grounders to get by. The Red Sox stuck him in relief at Pawtucket, though, rather than in the starting role he's been for nearly every appearance in his minor-league career, and to this point he's responded well. In 10 innings, Mortensen has 10 strikeouts against four walks, but he isn't getting his normal grounders.
Mortensen features a sinker, slider, and splitter, none of which are adept at missing bats, but the slider has induced many of his grounders. His fastball sits in the high 80s, and there isn't a ton of separation between his offerings, with a low 80s splitter working as his off-speed pitch.
Since he has an option, it's likely Mortensen is just up temporarily. The Sox might not even break his glass in case of emergency before Aaron Cook takes his spot on the roster once that move is made official.
His call-up also makes it seem more likely that Kevin Youkilis is headed to the disabled list, as there's only the one spot on the roster at the moment, following the demotion of Lars Anderson after Tuesday night's game. Then again, the team could demote Jose Iglesias, who was just called up Tuesday, now that Will Middlebrooks is in the majors. Iglesias remains in the clubhouse, though, and Youkilis believes he's 3-4 days from playing, anyway.