He left a camp game on Sunday against the Cubs in Mesa after two innings with what was described as tightness, but less than 24 hours later he said he was "feeling better than I was before I went out to pitch yesterday."
Having undergone an exercise program with the training staff, Pineiro reported that "all my strength is there. It's just that muscle that had to get loosened up."
He said he doesn't expect to miss a turn in the rotation during the opening week of the season, and manager Mike Scioscia confirmed that.
"Pineiro is feeling much better," Scioscia said. "He's being reassessed by our medical department. The little tightness is gone. Right now I don't think it's going to impact folding him in [to the rotation] earlier. We feel better about it today than last night."
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Sights & Sounds
Spring Training Info
With two open dates in the first week of the season on a road trip to Kansas City and Tampa Bay, Scioscia will have the option of holding back Pineiro if necessary.
"As of today," Pineiro said, "it looks good for the opening week."
It is unrelated, he said, to the strained oblique he sustained warming up for a July 28 start last year that cost him six weeks.
"It's the muscle where it connects to the lat [latissimus dorsi]," Pineiro said. "It had nothing to do with the oblique."
Comparing it to a "cramp that stiffened up," Pineiro said he would have continued pitching if it had been a regular-season game but felt no need to push it under those conditions.
"In a regular-season game, you figure out a way to adjust," Pineiro said. "You throw 84, 85, go with other stuff."
Pineiro reached 73 pitches in his previous outing and believes he's stretched out sufficiently to get deep into games after the season opens. His command all spring has been superb.
With threatening weather on the horizon, Angels ace Jered Weaver was sent to a Minor League game to get his work in, hoping to throw six innings against Arizona's Class A team in Tempe. Francisco Rodriguez assumed the projected start in a Cactus League game against the Cubs at Tempe Diablo Stadium.
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.