But the right-hander has been working hard behind the scenes to stay ready in case manager Terry Francona needs him out of the bullpen.
Matsuzaka wasn't needed in the Game 1 and Game 2 losses, but he will once again be there if Francona needs him for Sunday's Game 3.
"Well, what we've done is he's gone out and long tossed early, and we told him that we're not going to bring him in in the middle of an inning," Francona said. "That's not in his best interest. I'm sure he has some anxiety about that, but we've reassured him, 'Hey, if we use you, it will be clean innings, things like that.'"
All along, Francona's Plan A for this series was to bring back Game 1 starter Jon Lester on short rest for Game 4, which was essentially what took Matsuzaka out of the rotation for this series. This way, if the Red Sox can extend the series to the limit, ace Josh Beckett -- who lost Game 2 -- can pitch Game 5 on regular rest on Wednesday night in Anaheim.
"We wanted to use Lester [on three days' rest]," Francona said. "But again, we wanted to protect ourselves in case Lester had a ball off his leg or a long outing. And we told Dice that going in. He knew kind of what to expect. What it does, it does a couple of things aside from [Matsuzaka] pitching. It frees us up to use some other guys because he's sitting there maybe behind somebody with a lot of length."
After a rough first portion of the season, which necessitated a near three-month stint on the disabled list so he could strengthen his arm and reshape his body, Matsuzaka came back strong in September. In four starts, the righty went 3-1 with a 2.22 ERA.
That said, Matsuzaka kept a positive attitude about being utilized as a reliever for the Division Series.
"He was wanting to help out wherever he could," Francona said. "You get to this time of year, and most of the time, that's what guys do. I'm sure he would love to start. I hope he would like to. And I hope there's a time when he can. We thought this was in our best interest. We thought this was our best chance to win."
Matsuzaka has never pitched in relief in his three years with the Red Sox, but he had some experience out of the bullpen in postseason games during his professional career in Japan, and most famously, in high school, when he earned the win in relief a day after throwing 250 pitches in the Koshien tournament.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.