Rodriguez is out indefinitely after he was diagnosed with a Grade 2 right biceps strain following an MRI earlier this week, Jordan Bastian of MLB.com reports.
The Cubs are still mapping out a rehab schedule for the hard-throwing righty, but given the nature of the injury, he appears likely to open the 2020 campaign on the minor-league injured list. Rodriguez is expected to be assigned to Double-A Tennessee at the conclusion of spring training.