Good news on Kazmir

As the A’s wobble through a sluggish, injury- filled May, they received some encouraging news: Scott Kazmir’s MRI exam showed no structural damage in his left shoulder.

Kazmir left Wednesday’s start against Detroit after three innings, saying he had tightness in the shoulder. It was natural for the A’s to fear a serious injury and trip to the disabled list, but the MRI revealed merely “weakness” in the shoulder, according to manager Bob Melvin.

Melvin said he wasn’t sure if the A’s will put Kazmir on the DL; he was scheduled to visit a team doctor later Thursday. The A’s have an off day Monday, on Kazmir’s regular turn, and could skip him without disrupting their rotation.

“I think we’re looking at him just missing one start,” Melvin said.

Another injury update also offered some hope. A. J. Griffin, trying to come back from Tommy John surgery and shoulder soreness, pitched a simulated game before batting practice Thursday, throwing 30 pitches against teammates Ike Davis and Andy Parrino.

Griffin might throw one more simulated game before heading to the minor leagues on a rehabilitation assignment.

“It felt good,” Griffin said. “I felt like I was executing my pitches. It was good to get back on that mound and get the competitive juices going again.”

Melvin also said Sonny Gray, who took a sharp grounder off his right ankle in his last start, is fine and will start Friday night against the Yankees.

The news wasn’t as positive on outfielder Coco Crisp. Doctors recommended an epidural for Crisp’s lingering neck injury, and Melvin said the A’s expect Crisp probably will need to avoid baseball activity for at least a month.