For the first time since being shut down with tightness in his upper back 10 days ago, Matsuzaka was cleared to play catch on flat ground, doing so at distances of 60 and 90 feet.
He will progress gradually for roughly the next week and possibly get back to the mound after that.
"I have to see how I feel tomorrow. I don't know exactly how far behind I am. I don't know if it's going to take quite that long, but in my mind, one week sounds about right," Matsuzaka said through an interpreter.
Though his first exhibition start will come a little later than in a normal spring, manager Terry Francona is confident that Matsuzaka still has plenty of time to have a highly productive Spring Training.
"There's a progression that will have to take place," Francona said. "But the way the ball came out of his hand today, that was really encouraging. Now again, following it up will be just as important in how he bounces back. But that was real good. I wouldn't be surprised if he [comes back] fast, just because of all the work he's done to this point. There's a long way to go in camp. We'd rather not have that artificial deadline. When he's ready, that'll be the best time for us to get him out there."
Matsuzaka looks at the back injury as more of an annoyance than a setback.
"The plan for now is for me to throw every day," Matsuzaka said. "It's not like the time I went on the DL last year when it was a shoulder issue where we did incorporate some rest. This time, being a back issue, I really couldn't get into my natural delivery, but I felt I was able to do that today. I was able to focus on that, work on that, and I think that was the biggest thing for me today."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.