Updated

The Boston Red Sox have scratched pitcher Clay Buchholz from his scheduled start against the Philadelphia Phillies on Monday because of a collarbone injury.

Buchholz has irritation in his right AC joint, specifically, and the Red Sox will send right-hander Alfredo Aceves to the mound instead for the opener of a four-game home-and-home set with Philadelphia.

The hard-throwing Buchholz is off to strong start this season, having struck out 73 batters while posting a 7-0 record with a 1.73 ERA in 10 assignments.