Alzolay exited his start with Triple-A Iowa on Wednesday due to "slight biceps soreness," Tommy Birch of the Des Moines Register reports.
Alzolay allowed five runs prior to exiting in the bottom of the fourth inning with the injury. While the issue doesn't appear to be overly serious, the Cubs will likely proceed cautiously with the 24-year-old. It remains to be seen whether Alzolay will be forced to miss a start due to the injury.