The Rangers said Calhoun's contract was being purchased from Triple-A Round Rock before Tuesday night's game against Seattle. A corresponding move still had to be made to add the second baseman/outfielder to their 40-man roster.
Calhoun was one of three minor leaguers the Rangers received from the Los Angeles Dodgers in the July 31 trade that sent Darvish to the National League's top team.
Known more for his hitting, Calhoun played mostly left field for Round Rock after playing second base in the Dodgers organization. The 5-foot-8 left-handed hitter batted .300 with 31 home runs and 93 RBIs in 128 Triple-A games this summer.