Beckett said he was feeling better while revealing that the injury was there prior to his career-high 126-pitch outing on April 29.
"I felt a lot better today than I did the day before my last start," Beckett said. "We'll have to see how things progress. If I come in and feel [bad] tomorrow, I'll probably back off a little bit."
"He said he felt normal today," manager Bobby Valentine said. "[He] said his lat felt normal today, and then he said, 'Whatever normal is for me, but I felt normal' and he's right on schedule."
If Beckett misses just the one start, then the Red Sox would seem to have effectively gotten ahead of the matter. But that doesn't mean the Sox wish they hadn't known sooner. Beckett said he had been bothered for a week and blamed himself for not speaking up, while Valentine indicated it was pitching coach Bob McClure and the training staff whose job it was to say something.
"It's kind of been there for about a week, kind of leading into my last start," Beckett said. "You can always, on your start day, make yourself believe that things are better than they are. I really wanted to pitch. I wound up making things worse. ... I probably should have been a little smarter before my start and maybe brought something up."
Valentine called the communication matter "a snag."
"In retrospect, it would've been nice to know that," Valentine said of the injury. "We have a system set up to have information flow, it just seemed like there was a little snag there. I don't think it's up to [Beckett] to come into the manager's office. You know, you talk to pitching coaches all the time and trainers all the time. That information usually flows up."
Once the injury became known, the Red Sox did not give Beckett a say as to whether he starts Saturday, when Aaron Cook will make his season debut instead.
"They didn't really give me a choice," Beckett said. "Bobby came into the training room and said, 'You're going to miss a start.' It wasn't totally shocking when he came in and said it. It was definitely something that was discussed before that. It felt a lot better the other day. I'm pretty optimistic this next start is going to be fine."