Double-A Hartford placed Veen on its 7-day injured list July 27 with a right thumb injury, MLB.com reports.
Veen missed five and a half weeks in May and June with back and left hand injuries before returning to the Hartford lineup shortly before the All-Star break, but he played just eight games for the Double-A club before succumbing to a new injury. Rockies player development director Chris Forbes indicated that the club didn't have a timeline for Veen's return to action.