Wood was placed on the 15-day injured list with a left shoulder impingement Saturday.
Wood has been dealing with the issue for a while, Maria I. Guardado of MLB.com reports, which may explain his 13.86 ERA over his last three starts. The move was made retroactive to Thursday, so Wood will be eligible to return Sept. 16, but the Giants haven't decided whether or not to shut him down for the season. The team has been all but eliminated from playoff contention, as it sits 10 games back of the sixth seed, so Wood may simply start his offseason early in an effort to be as healthy as possible heading into next season.