Ramirez has been bothered by the injury for the past two weeks. He is suffering through the worst season of his career, hitting .168 with five home runs and and 22 RBIs in 179 at-bats.
Ramirez missed 80 games in 2009 and was out two months with a left shoulder separation.
Ramirez is striking out at a record pace for him with 45 strikeouts in 47 games. His .285 slugging percentage is the lowest on the team.
In a corresponding move, the Cubs are expected to select the contract of veteran infielder Chad Tracy from Triple-A Iowa. Tracy is batting .396 with five home runs and 18 RBIs in 91 at-bats with Iowa.
Bruce Levine covers baseball for ESPNChicago.com.