Castellanos, 27, was acquired by Boston in a trade with the Los Angeles Dodgers in October and was designated for assignment on Dec. 12 when the club re-signed Mike Napoli. Castellanos brings the Rangers' total on the 40-man roster to 40. Castellanos had played the last two seasons in the Los Angeles organization.
More background on Castellanos from the club's release:
The Miami native appeared for the Dodgers in each of the past two seasons, including eight games in 2013, since he was acquired from St. Louis in the July 31, 2011 Rafael Furcal trade. He appeared in 24 total games in the majors in 2012-13, batting .171 with two home runs and four RBIs. The right-handed batter and thrower spent the bulk of last season with Triple-A Albuquerque, batting .257 with 19 home runs and 61 RBI in 105 games. He owns a career .288 average in the minor leagues, where he has seen significant action at all three outfield positions, as well as third base and second base.