But his pitching wasn't the only thing off. Matsuzaka is also battling back problems and may need time on the disabled list to deal with the injury, according to ESPN.
"[Matsuzaka] went out with a crink in his neck, and we were hoping he was going to work through it," Red Sox manager Bobby Valentine said of the Monday night start.
The tightness is in the same spot where Matsuzaka was hurting in May, when he was coming back from Tommy John surgery and had to adjust his workload to deal with the new injury. Matsuzaka said the neck issue came up again this week, and he skipped his usual bullpen.
"I focused on getting myself in condition to be able to pitch tonight, and I went out there, but I ended up not being able to get my arm through," he said.
Now that the Red Sox know the injury won't just work itself out, they're considering sending Matsuzaka to the disabled list, especially with the All-Star break right around the corner.
Starting pitcher Clay Buchholz is already on the DL, while Josh Beckett just finished a 15-day stint of his own. Aaron Cook, who has been summoned to help the rotation, has also been injured for some time this season. In addition to the starting pitching injuries, Boston has seen a handful of relievers and all of its outfielders hit the disabled list at least once this season.
Matsuzaka has pitched five games for the Red Sox, logging up to six innings only once. He is 0-3 with a 6.65 ERA and 20 strikeouts in 23 innings pitched.