Butto will miss the next 2-4 months after undergoing surgery Saturday to remove a blood clot from his right arm, Justice delos Santos of The San Jose Mercury News reports.
Butto was diagnosed with a blood clot after leaving his appearance Wednesday against San Diego with arm fatigue. The recovery timeline leaves room for him to return to the Giants' bullpen before the end of the season, though that likely won't happen until closer to or after the All-Star break.