Daisuke Matsuzaka has been placed on the 15-day disabled list, Red Sox manager Terry Francona said Sunday, and he hinted it could take months for the struggling righthander to recover.
"It's not going to be a two-week DL thing," said Francona. "We have a lot of work ahead of us to get him back to being Daisuke."
Matsuzaka had an MRI done yesterday that showed "a little bit of weakness in his shoulder," but there is no true structural damage.
"We don't know all the specifics yet, but it's not an injury [that has led to his struggles]," said Francona.
Matsuzaka will be sent to the Red Sox spring training complex in Florida when he begins his rehab. There is no timetable for his return.
"We're going to start figuring this out," said Francona. "If he has shoulder weakness, it's not like he's going to come back and pitch and his shoulder is going to be miraculously strong. I don't have all the answers yet."
Matsuzaka agreed with the decision, but noted that it wasn't entirely his choice to make.
"It was partly the club's decision. I also felt I couldn't keep going the way I was going, so they had to make changes," Matsuzaka said through an interpreter. "I thought that, if I keep going like this, I was going to be a burden to this team."
Matsuzaka said he approached the coaching staff first.
"I wanted to approach them and I wanted to be prepared to be taken out of the rotation," said Matsuzaka.
"Through the whole thing, he was very cooperative," said manager Terry Francona.
Matsuzaka says the MRI diagnosis confirmed some of his feelings in his shoulder.
"I had some awareness. I could tell there was some weakness," he said. "But fatigue is something that happens to everyone."
Francona attributes at least some of Matsuzaka's woes to his heavy use in the winter's World Baseball Classic.
"I know the MLB wants to have players play it if they're able, but, right now, we're down a pitcher," said Francona. "The fact is, we had a guy who won 36 games in two years and now we don't have him. That's hard."
Francona said that Matsuzaka wasn't able to form a "consistent base" from what he believes was an interrupted offseason.
"Every pitcher in spring training pitches two innings in their first start," he said. "He's out there pitching all these innings and trying to figure out ways to get outs before he needs to."
Matsuzaka doesn't think that the World Baseball Classic had too much to do with his 1-5 record.
"It was my fault I couldn't make that transition effectively," said Matsuzaka.
While talking about the World Baseball Classic, Francona's cell phone rang twice.
"That might be the league telling me to shut up," he quipped.
Matsuzaka is 1-5 with an 8.23 ERA. He gave up six earned runs on eight hits and four walks in his last start, an 8-2 loss to the Braves Friday night.
Catcher Dusty Brown was called up from Pawtucket to fill Matsuzaka's roster spot. He will be in uniform on the Red Sox bench today against the Braves.