Wheeler's fastball dipped in velocity as the season progressed, which, when coupled with his lack of command, indicates a potential shoulder injury, according to Zimmerman.
Wheeler missed his final start of 2013 due to shoulder stiffness, Terry Collins told reporters in late September. However, despite Zimmerman's concern, the stiffness was attributed to fatigue and did not require any further testing.
It’s not uncommon to see young pitchers struggle to find their command in their debut seasons. However, considering Wheeler has a history of these problems does concern me to a degree. He knows it’s a problem - he’s been talking about this challenge since he came to the organization. Those in the organization I’ve talked to about Wheeler have said his ability to repeat a delivery is crucial for him, but - if he can do that - the sky is the limit for him going forward.
Read More: Zack is Wheeling a Couple Concerns (Zimmerman, FanGraphs)