Rays manager Joe Maddon said the side sessions will "be able to tell us a lot" regarding whether the two starters will be ready to return during the latter half of the team's West Coast trip, most likely at Anaheim. Niemann said he and Davis had been throwing since Thursday and have felt better each day.
"Everything's going well," Niemann said. "It's more just me out there working on my stuff. The arm is feeling really good. Yesterday was a really good day. I was throwing the ball and letting it go a little bit. I'm just going to try to get my stuff back and try to figure out where everything's at -- breaking stuff, offspeed [pitches] and all that, just try to fine-tune that and get back out there."
Both pitchers had MRIs that Niemann said came out "clean." They revealed slight strains, but it was nothing more serious than the original diagnosis.
"We caught it at the right time," Niemann said. "It's good we caught it when we did. It was a decision made on the fact that we'd rather do it now than do it in September and keep fighting it through the rest of the season. If we take a week or two now to get things right, it's OK to do that and be ready for the push we're going to make late in the season."
Niemann said he began feeling the pain the day after his previous start on Aug. 3 against Minnesota. The right-hander said it felt "extra sore," and he realized after the pain lingered on a few days that it was more than just the usual day-after soreness.
While nothing can be determined for sure until after the bullpen sessions on Monday, Niemann said he and Davis were still hoping to get back in the rotation on back-to-back days in Anaheim.
"That's what we're shooting for," Niemann said. "It's going to depend on tomorrow. Tomorrow's the only thing set in stone."