Matsuzaka worked seven scoreless innings in his rehab start for Triple-A Pawtucket on Tuesday at McCoy Stadium in Pawtucket, R.I. He allowed only one hit with four walks and seven strikeouts, tossing 102 pitches (59 strikes) before leaving after facing two Rochester Red Wings batters in the eighth inning.
The right-hander was at Fenway Park on Wednesday and deemed himself healthy and ready to pitch for the Red Sox. He could be in line to start against the Kansas City Royals on Sunday, but the Red Sox have provided no official word.
"After my last start down in Pawtucket, I told [manager] Bobby [Valentine] and [pitching coach] Randy [Niemann] that I felt good and I was ready," Matsuzaka said. "I haven't spoken with them this time around, but I'll be speaking to them soon, and I think a decision will be made then."
Red Sox left-hander Felix Doubront has been on the DL since Aug. 10 with a right knee contusion. He's also set to be activated this weekend and is another option for Sunday's start. Doubront was up and down four times during a bullpen session Tuesday.
Matsuzaka, meanwhile, was pleased with his latest performance for Pawtucket.
"It's the first time I threw deep into a game in a while, and my body feels fine today," he said.
Valentine mentioned during his daily pregame news conference that Dice-K has a sore calf, which the pitcher said he's not worried about.
"The reports were good," Valentine said. "He threw the ball well, he kept it down, had his locations and mixed his pitches. He came out of it all right, just a little sore calf is all I hear. All of the things that we were dealing with seemed to be OK."
Matsuzaka had Tommy John surgery on June 10, 2011, and returned to the rotation in less than a year. However, he's made only five starts for Boston this season, going 0-3 with a 6.65 ERA. He's made 11 minor league rehab starts for the PawSox this season.
"After I had the surgery, my body definitely feels better than it did before, which is a good thing," Matsuzaka said. "But it's definitely been stressful and frustrating to have to fight through all these injuries, but I think I'm finally at a good place and I'm looking forward to getting better and better every time I pitch."
Matsuzaka's six-year contract with the Red Sox will expire after this season. There's been no indication the team might want to re-sign the oft-injured pitcher, but Matsuzaka said he wants to remain in the majors and would like to do that in Boston.
"I've really enjoyed my time in Boston and my family has also enjoyed our time here, so of course I would like to, but it's a little early to say where I'm going to be, or even talking about that," Matsuzaka said. "No matter how long I'm going to be here, I'd like to wear this Red Sox uniform with honor and play hard for the rest of the season and do what I can to contribute to the team."