Sheffield, who missed his third straight game on Tuesday, had his ailing right shoulder examined by Dr. Stephen Lemos as scheduled. No structural damage was found, and the pain he has been dealing with is believed to be slow progress in the healing process following labrum surgery last October.
Sheffield received two cortisone shots -- one for the right shoulder, the other for the left. The latter, he said, had flared up on him from trying to compensate for the injury to the right one. That will alleviate the pain for now, but he's going to make a bigger effort from here to strengthen the right shoulder.
"What I'm doing now is something that I think I should've been doing in Spring Training, rehabbing it and not trying to get at-bats," Sheffield said. "I should've been getting it a lot stronger, but what I'm going through now, I'm paying for what I didn't get to accomplish in Spring Training -- get rid of the scar tissue, let the pain come in and get it treated and rehabbed more. And then get it to the strength that I need it to be."
Head athletic trainer Kevin Rand said that was just Sheffield beating himself up in hindsight. The shoulder felt fine in Spring Training, and the early work he put in swinging the bat before Spring Training began seemed to be paying off. Now, Sheffield said, he'll play catchup by coming in early to do his shoulder work before doing his baseball work.
How soon he'll be back playing depends on the cortisone shot. He returned from a shot last year missing only one day, but he said on Tuesday that he could take a couple extra days and follow the recommended time.
Polanco, meanwhile, was diagnosed over the weekend with an inflamed nerve in his back. He's on a combination of rest and medication, but he hopes to do some early hitting work on Wednesday afternoon with an eye towards returning to the lineup Wednesday night.
Back problems are nothing new for Polanco, who has been dealing with them since Spring Training. It was numbness in his left leg on Friday night that convinced him something was more seriously wrong. There's still no idea how the nerve flared up; the only play Polanco could think of from Friday was a slide into second on the artificial surface at Toronto's Rogers Centre.
However, Polanco said, doctors are confident that once the inflammation goes down, it should not be a problem for him again.
"I'm feeling a lot better," Polanco said. "I felt better from [Monday] to [Tuesday]."
Jason Beck is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.