"Like with a lot of guys, we're going to use the final two months to audition Mike and see if he can be a part of a winning situation in 2015 and beyond," assistant general manager Thad Levine said. "He will get an opportunity."
Carp, a left-handed hitter, was used sparingly by the Red Sox this season as he hit just .198 in 42 games. He had a more significant role last year, playing in 82 games and hitting .296 with a .362 on-base percentage and a .523 slugging percentage.
He has played in 131 games in his career at first base and 105 in the outfield. He also pitched one inning so the Rangers have a new emergency reliever.
The Rangers made room on the 40-man roster by putting Alexi Ogando on the 60-day disabled list. They will have to make a move on the active roster before Monday's game.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger This story was not subject to the approval of Major League Baseball or its clubs.