Miller, who was 7-7 with a 3.35 ERA in 15 starts before going on the disabled list June 29 with a season-ending rotator cuff injury, passed a physical exam Wednesday in Boston and agreed to a contract with a $1.5 million base salary and $3 million in incentives. Agent Bob Garber said the deal will be finalized on Thursday.
Los Angeles, Arizona, Oakland, Texas, Florida, Detroit, Kansas City and the New York Mets were among the other clubs that expressed an interest in Miller, who has a 58-39 record in five big-league seasons.
Miller, who made $3.4 million last season, became a free agent when the Astros decided not to offer him a contract by the Dec. 20 tender deadline.
"The Red Sox were right on it from the beginning," Garber said. "They flew him to town and made him feel welcome. That's what Theo Epstein does. He makes players feel wanted, and they want to come here."
Garber said that he expects Miller to be ready to pitch by Opening Day. If that's the case, Miller will join Curt Schilling and new free-agent signees David Wells and Matt Clement at the top of a revamped Boston rotation.