The Rangers, who begin a three-game series in Cleveland tonight, assigned Spilborghs to the Triple-A Round Rock roster.
Spilborghs, 32, signed a Minor League contract with an invite to Spring Training with the Indians during the offseason. He competed in an open competition for the starting left field spot, but lost out to Shelley Duncan. Johnny Damon also joined the team on Tuesday to share time in left.
Spilborghs has been playing with Cleveland's Triple-A affiliate, the Columbus Clippers, for whom he hit .250 with one home run and 13 RBIs in 21 contests.
Spilborghs is a career .272 hitter in seven years with the Rockies. He batted .210 with three homers in 98 games for Colorado last season.