The A’s have acquired right-handed pitcher Sandy Rosario from the Boston Red Sox in exchange for cash or a player to be named later. The 27-year old Dominican pitcher has spent most of his career in the minors and has only pitched in 10 games at a Major League level. Over 7.2 innings he has a career 15.26 ERA, a .526 BABIP, a 6.58 FIP and a 4.70 SO/9 rate (and a 3.52 BB/9 rate). He pitched in four different levels for the Miami organization last season, spending most of his time in Triple-A where he combined for a 1.04 ERA, .278 BABIP and 1.76 FIP over 26 innings.
In a corresponding move the A’s designated outfielder Jermaine Mitchell for assignment to make room for Rosario on the 40-man roster. Mitchell, who was most recently named as the A’s eighth top prospect by Baseball America in 2012, was drafted by the A’s in the fifth round of the 2006 draft. He spent the 2012 season in Triple-A Sacramento, posting a .252/.345/.386 slash line with a .331 wOBA and 92 wRC+ over 474 plate appearances. His most recent success was in 2011, when he combined for a .332/.430/.530 slash line, 15 HR and 27 stolen bases over 635 plate appearances between Midland and Sacramento.
With the A’s already “crowded” outfield and Michael Taylor available to take over if an injury occurs, I really don’t see there being much room for Mitchell in Oakland. I could very well see someone claiming him off of waivers as he has showed some potential just over a year ago. However, he is 28 years old and has never seen a plate appearance in the Major Leagues.