BOSTON — The Boston Red Sox placed right-hander Clay Buchholz on the 15-day disabled list and called up left-hander Andrew Miller from Triple-A Pawtucket.

Buchholz’s strained lower back had been bothering him for a few starts.

Miller signed as a minor league free agent during the offseason. He is scheduled to start Monday against San Diego. He was 3-3 with a 2.47 ERA in 13 games – 12 starts – with Pawtucket.

Buchholz is 6-3 with a 3.48 ERA. He is coming off a career-best 17-7 record in 2010.