Returning from Tommy John surgery, Matsuzaka's been bothered by the left side of his neck, particularly out of the stretch.
"Daisuke came up here and he had a little neck issue that we wanted to make sure felt perfect before he threw a 'pen again," manager Bobby Valentine said Friday. "So we kept pushing the 'pen back. I should've told you all. He wasn't really scheduled to pitch today, even though we wanted a lot of the press to go there, help out the economy in Toledo [where Pawtucket would've been].
"We talked on, I guess, Tuesday and Wednesday, and we said we'll revolve his next start around his bullpen availability, his neck condition. Today is going to be his bullpen day -- or tomorrow, depending on how he felt when he played catch -- and he can pitch Monday. I think we'll have better weather. Initially, the [thought of a pushback from Friday] was the weather concern, and then it became a neck concern.
"It's his left side. Out of the stretch mainly. It had nothing to do with his throwing -- [he] felt great throwing. Rather than having him pitch with any kind of ailment, we got it better. He feels great."
Instead of pitching on the road, Matsuzaka's first start for Pawtucket is scheduled at home, against the Twins' Triple-A club, Rochester, in a 6:15 p.m. ET start.
Pitchers can rehab in the Minor Leagues for a maximum of 30 days. Matsuzaka's first rehab game was April 23, and Valentine projected Matsuzaka would have two Minor League starts (including Monday's) or maybe three, if Monday's outing is brief -- but that would seem to be too few if Matsuzaka is to pitch on an every-five-days schedule.
"As many [outings] as he thinks he needs," Valentine said. "But there is a rehab assignment date which becomes a technicality, which should give him at least two more starts."