Mayve he is taking too many swings during batting practive for Interleague:
Carlos Zambrano has been banned from batting practice.
The Cubs think his arm soreness stems from him taking too many swings, as opposed to him throwing too many pitches. This is turning into quite a saga, and the fact he threw 136 pitches in his last full outing still seems like the obvious answer to the questions surrounding his injury. However, the batting theory takes some of the heat off Dusty Baker, if people are buying it.