Wacha (oblique) exited Tuesday's rehab start at Double-A Springfield with an apparent injury, Derek Shore of The Cardinal Nation reports.
Wacha lasted less than three innings before leaving the game, and allowed five earned runs on six hits while throwing 52 pitches. It remains unclear whether the 27-year-old aggravated the oblique strain that landed him on the disabled list in mid-June or if he is dealing with a new injury, but it remains a worrying development regardless.