Is this the 2007 version of Matsuzaka who was spectacular at times, inconsistent at others, but ultimately good enough to win Game 7 of the American League Championship Series and Game 3 of the World Series?
Or, better yet, is this the 2008 model, who was exasperating to watch (94 walks in 167 2/3 innings) but undeniably successful (18-3, 2.90 ERA, .211 opponents' batting average and fourth in the AL Cy Young Award voting)?
The one pitcher nobody wants to see -- particularly not Dice-K himself -- is the guy who went 1-5 with an 8.23 ERA in his first eight starts of a 2009 season that has already been interrupted by two stints on the disabled list.
Fact of the matter is, the 29-year-old Dice-K is finally back, but nobody truly knows who he is yet.
"He kind of evolved the last couple of years," said Red Sox manager Terry Francona. "He got away from the guy we had signed for a few different reasons. I think what we're hoping to do is see closer to the stuff that we saw when we signed him. You might not see the exact same stuff. I don't know if that's fair. But get closer to it this year, [and hope] that during the winter then when he comes back next year, we're back to that guy with a better comfort for pitching here and living here culturally and competing."
The one thing Red Sox fans will immediately notice when Matsuzaka steps back on the hill is that he's leaner and firmer than the man they last saw the night of June 19, when he was booed off the mound after giving up eight hits and six runs over four innings against the Braves.
"He has done an outstanding job of committing to a program and getting himself in what we consider, just from the naked eye, better shape," said Red Sox pitching coach John Farrell. "He's reshaped his body. He's added core strength. He's gotten the strength levels in his shoulder back to a level where he was a year ago. I think he feels good about himself as well, so we're all looking forward to his next time out here."
Nobody more than Matsuzaka.
"I know that it took me some time to get here, but I also feel that I was able to use that time to get prepared really well, and I just hope that I can apply all those things that I was preparing for in my start," said Matsuzaka.
Once the decision was made by the Red Sox to shut Matsuzaka down, they opted to sacrifice most of his 2009 season to try to maximize what he can do for the rest of his time in Boston. He is under contract with Boston through 2012.
There was a physical makeover that included countless hours in near-solitude at the team's training facility in Fort Myers, Fla. And as Matsuzaka got his body in vastly improved shape, he started to rebuild the confidence that was ravaged by AL hitters during his ill-fated stints in the rotation earlier this season.
"Of course, I'm excited," Matsuzaka said when asked his thoughts about rejoining his team just in time for crunch time.
When Matsuzaka first left for Florida nearly three months ago, he was clearly down. For the first time in his professional life, his confidence was completely deflated. These days, the righty sounds like a man who has the perspective of knowing that sometimes you have to reach bottom to get things going back in the right direction.
"I think it was a difficult season, but I also firmly believe that the experiences I had this year are going to help me going forward," Matsuzaka said.
"He's motivated, there's no doubt about that. Again, to his credit, he didn't turn his back on the remainder of this season and that's obvious by the commitment he's put into this work. He's a fierce competitor. I think that natural instinct in him will bring out the ability he has currently to do what he can for our team."
-- Red Sox pitching coach John Farrell, on Daisuke Matsuzaka
Those who work the closest with Matsuzaka can sense his inner desire to be a man the Red Sox can count on down the stretch.
"He's motivated, there's no doubt about that," said Farrell. "Again, to his credit, he didn't turn his back on the remainder of this season and that's obvious by the commitment he's put into this work. He's a fierce competitor. I think that natural instinct in him will bring out the ability he has currently to do what he can for our team."
While Matsuzaka is driven, his teammates are curious and intrigued to see what kind of pitcher they are getting back.
"This ballclub really counts on Dice-K," said Red Sox slugger David Ortiz. "I know he's been through some stuff this year, but he's a good pitcher. He's a good teammate. He's a good guy to have around. Hopefully, he can come back and do what he knows how to do."
The Red Sox are fortunate in that they currently have three starters pitching at a high level in Josh Beckett, Jon Lester and Clay Buchholz. But with venerable knuckleballer Tim Wakefield's balky back leaving him day-to-day for virtually the rest of the season, the Red Sox could badly use one more starter to step up.
"We know how good he can be," said Red Sox left fielder Jason Bay. "I think for us to go where we want to go, he's going to have to be that guy again. I hope he doesn't try to be that guy right away. Give him a little time. At the same time, yeah, we're excited to get him out there. We had him for the first month of the season, and he's kind of been the forgotten man a little bit. He's been in Florida forever and you don't see a lot of him, and boom, you realize he was a huge part of our team last year. It would be nice if he could give us some of that."
With 20 games left, the Red Sox have a four-game lead over the Rangers in the AL Wild Card standings. Assuming they get to October, Matsuzaka has four starts before then to prove that he belongs in the postseason rotation.
"I don't think it's really necessary to think that far ahead right now," Matsuzaka said. "I'd like to focus everything I have on my upcoming start."
Does Farrell, whose job is to plan for the short and long term, think Matsuzaka has enough time to get himself right?
"That's all that's allowed at this point because of the schedule," Farrell said. "That progression has been going in a positive way. Again, I think the credit needs to go to him, the work he's put in to allow himself to come back with the ability to contribute in the last month of the season. It could really give us a boost in the arm here for him to step back in the rotation. Any time you take a 15- to 20-game winner and insert him back into your rotation, it's a positive."
"It'll be big for us if Daisuke comes back and is Dice," said Lester.
Just who is Dice? The right-hander's latest attempt to answer that question begins on Tuesday.