ST. PETERSBURG, Fla. -- Rocco Baldelli had been playing well for the Devil Rays. Just as important, he had been playing every day without any limitations from the hamstring injuries that forced him to miss the first two months of the season.

Which made it even more concerning when he woke up Thursday with soreness in his right hamstring that forced him to miss the game against Detroit, sidelined him again last night and, most troubling, could again make his availability to play daily a question.

"It doesn't feel good, so I guess it's concerning," Baldelli said. "As of right now it's going to be a small step back regardless, so I don't really know where it's going to go. I'll find out every morning when I wake up."

Baldelli, who is hitting .285 and moved into the leadoff spot, aggravated the hamstring when he beat out an infield single in the fifth inning Wednesday. By Thursday morning, he knew it might be a problem.

"I woke up [Thursday] morning, and it was pretty sore and that was pretty much it," he said.

Baldelli's early season injury was described as a left hamstring problem, but that doesn't mean the latest injury is a new one. He said Thursday that both hamstrings were sore during the spring as he worked his way back into form after missing last season due to left knee and right elbow surgeries.

"Both of them were bothering me," he said. "Even though the left one was the initial one, neither one is really my good one or my bad one."

Baldelli said he had been through so many injuries, he didn't dare guess how long this would be an issue.

"I'd been feeling fine," he said. "I wouldn't say 100 percent, but good enough to get out there and play every day. I guess we're going to play it day by day and see how it feels every day when I show up and do treatment on it and do the regular racket."