Sanmartin suffered a minor quadriceps strain during a recent exhibition game appearance for Team Colombia, Susan Slusser of the San Francisco Chronicle reports.
Sanmartin tweaked his quad while fielding a comebacker. The lefty will be forced to pull out of representing his native country in the World Baseball Classic, and he will be reevaluated before it's determined how much time he might miss. Sanmartin was a waiver claim of the Giants back in November.