Giants left-hander Barry Zito sprained his right ankle during a rehabilitation start for Triple-A Fresno. The veteran will be sidelined indefinitely. Zito was already on the disabled list with a sprained right foot that has hampered him since April. "I saw a picture of the ankle, and it's pretty bad," Giants manager Bruce Bochy said. "It's really swollen. It looks like there's a baseball in there, so this looks like it's going to be quite awhile."