SAN DIEGO — San Francisco Giants pitcher Joe Martinez has a concussion and three small fractures in his head after being hit by a line drive.

The rookie reliever was stable and alert in a San Francisco hospital Friday, and the Giants said he was expected to make a full recovery. Martinez will remain hospitalized for observation over the next three or four days.

Martinez was struck by Mike Cameron's line drive on Thursday night, and sustained hairline fractures on the right side of his face. The accident occurred with two outs in the ninth inning of the Giants' 7-1 win over Milwaukee.

The Giants put Martinez on the 15-day disabled list and purchased the contract of right-hander Justin Miller from the minors.