The Rockies placed Matsui on the 15-day disabled list with lower back spasms that he suffered during Saturday night's 5-4 loss to the Diamondbacks, and recalled Clint Barmes from Triple-A Colorado Springs.
Matsui suffered through back problems much of last season with the Mets and the Rockies. By the time he joined the Rockies in August, after spending time at Colorado Springs and on the Triple-A DL, he had to go through a rigorous stretching and strengthening program before every game.
This winter, Matsui concentrated more on sprinting and running activities.
But now, "it looks like I'll have to do that [special back workout] when I come back," said Matsui, who said he hopes to have an MRI exam performed when the team returns to Denver after Sunday afternoon's game against the Diamondbacks.
Matsui has been arguably the Rockies' most consistent offensive regular. He has a .361 batting average with two doubles and a triple, three RBIs and a team-best 5-for-5 in stolen bases. On Saturday, manager Clint Hurdle said Matsui was showing why he was so highly coveted out of Japan a few years ago.
"Most importantly, Kaz deserves the credit, because he went through a very difficult stretch," Hurdle said. "You come over to a place and big things are expected. You're not a master of the language to start with, which is difficult, and nothing goes right. And he's able to put it back together."
Matsui said he is unsure whether he was injured chasing Tony Clark's bloop double or on a subsequent swing.
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Also, he isn't certain why he has been prone to back problems. After signing a $20.1 million contract with the Mets in 2004, he was having a strong rookie year but suffered a lower-back strain in August and struggled the rest of his time with that club.
Carroll steps in: Early last season, Luis Gonzalez started at second base to begin the season, but various problems with joint inflammation opened the door for Jamey Carroll, who batted .300 and earned a two-year, $4 million contract.
Now Carroll steps in again, this time for Matsui. Before batting second in Sunday's lineup, Carroll had made three starts, two at second and one at short. He had a .385 batting average with two RBIs.
"That's the strength of having Jamey on your roster and having him available," Hurdle said. "You plug him right in. You lose some of the basestealing opportunity, but we know he can handle the bat, we know he can play defense, and he competes very well."
On the Rox: Right-hander Brian Lawrence gave up six runs and 10 hits in an injury rehab start for Colorado Springs at Tucson. ... Barmes, a shorstop by trade, was in the Colorado Springs lineup for what would have been his first start at second base. He could be used at either position with the Rockies. "I felt comfortable down there, the few games that we had," said Barmes, noting that bad weather cost Colorado Springs several games.
Up next: The Rockies being a seven-game homestand on Monday with the first of two games against the Giants. Left-hander Jeff Francis (1-0, 2.84 ERA), pitching on six days of rest to accommodate a five-game suspension he received for throwing behind a batter during Spring Training, will face Giants lefty Barry Zito (0-2, 8.18 ERA), whose start was backed up because of bad weather in Pittsburgh.
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.