OAKLAND -- Daisuke Matsuzaka told the Red Sox several days ago that he was again being bothered by his right trapezius muscle (ranges from the neck to shoulder to upper back), and wouldn't be able to throw his usual bullpen session in-between starts.
But Matsuzaka insisted that he was fit enough to make his scheduled start as the Red Sox opened a three-game series in Oakland.
Turns out, he wasn't.
Matsuzaka was rocked for five runs in just over an inning's worth of work, putting the Red Sox into an early hole out from which they couldn't climb in a 6-1 loss to the A's.
"Obviously he didn't have his good stuff tonight," said Valentine. "We were hoping he was going to work through (the issue). (He mentioned it) a couple of days ago, but it seemed like he worked through it. He said he was going to be alright to pitch. We asked him pretty consistently.
"It got rubbed out the other day in Seattle."
Matsuzaka allowed a solo homer to Josh Reddick in the first, then came unglued in the second, as the first five hitters of the inning reached base. Included in there was a three-run homer by another former Red Sox outfielder, Brandon Moss.
He left after an inning, tying his shortest outing since joining the Red Sox.
"Leading up to the start, my neck tightened up a little bit and I ended up not being able to throw a bullpen," he said. "I focused on getting myself into condition to be able to pitch tonight. I went out there, but I ended up not being able to get my arm through."
Matsuzaka has battled this same issue twice earlier this season -- once in spring training, and then again in May, when he was nearing the end of his rehabilitation assignment. Both times, he received injections to the area.
Matsuzaka is now winless in five starts since returning from Tommy John surgery
Asked if placing Matsuzaka on the disabled list was a possibility, Valentine said: "Oh, I don't know. With the All-Star break, possibly."
"I just spoke to Bobby about what needs to be done," said Matsuzaka, "and a decision will be made sooner than later."