Rodriguez (biceps) was optioned to Double-A Tennessee on Friday.
Rodriguez is out indefinitely with a Grade 2 right biceps strain, but he was never a candidate for the big-league roster, as he's yet to play above High-A. As he has no big-league experience, the Cubs are allowed to option him now rather than placing him on the major-league injured list. It looks likely that he'll open the season on the injured list in the minors, however.