Castellanos, a right-handed batter, appeared in eight games for the Dodgers last season, going 3-for-18 with a home run, and also appeared in 16 Major League games in 2012. He spent the majority of '13 in Triple-A, where he hit .257 with 19 home runs and 61 RBIs in 105 games.
Castellanos' addition gives the Rangers a full 40-man roster.
Cash Kruth is a reporter for MLB.com. Follow him on Twitter at @cashkruth. This story was not subject to the approval of Major League Baseball or its clubs.