Matsuzaka threw on Friday before the start of Boston's series against the Cincinnati Reds. He's eligible to come off the 15-day disabled list any time.
Manager Terry Francona said Matsuzaka will pitch on Monday for Triple-A Pawtucket against the Philadelphia Phillies' Lehigh Valley team in Allentown, Pa. Matsuzaka will throw about 80 pitches. He could pitch for the Red Sox five days later if all goes well.
Matsuzaka went on the disabled list May 30, retroactive to the 28th, with a strained rotator cuff.
"He's done fine," Francona said. "We kind of knew where we stood on this whole thing. As long as there's not a bump in the road, which I don't think anybody thought there was, he's doing fine."
Matsuzaka is 8-0 with a 2.53 ERA in 11 starts this season. He went on a program to strengthen his shoulder while he was sidelined.
"Because the team continued to win and Justin Masterson filled in and did really well, I didn't feel so much frustration being unable to play," he said through a translator. "I could take time to heal up and get better."
Catcher Jason Varitek was out of the lineup for a second straight day with a sore throat. Francona said he could be back in the lineup on Saturday.
Francona plans to give outfielder Manny Ramirez a day off Saturday to rest his hamstring. Ramirez sat out a game last Saturday with a sore right hamstring.