The Red Sox made official what had been rumored for a day when they placed Mike Lowell on the 15-day disabled list Thursday, making room on the roster for right-hander Daisuke Matsuzaka, who is scheduled to start against the Colorado Rockies.
The official injury for Lowell is a strained right hip, which he had surgically reparied after the 2008 season. He told reporters in Denver on Thursday that he felt a "twinge" when running to first base while making the final out Tuesday.
The 36-year-old Lowell, who has questioned his role as a little-used reserve, also said he has felt some guilt about taking a roster spot. He has appeared in just 31 games, while starting in only 18.
Lowell is batting .213 with two home runs and 12 RBIs this year.
Matsuzaka missed two starts while on the DL with a right forearm strain. He threw eight shutout innings June 7 in Cleveland in his last start, improving to 3-1 with a 1.98 ERA over his previous four outings.
The 29-year-old Matsuzaka began the season on the DL with a neck strain. He is 5-2 with a 4.59 ERA in eight starts overall.