He has been trying to think back over the last several games to a play that may have tweaked his knee, but hasn't been able to pinpoint the cause. He knows that it has been a problem here, and that it flared up Tuesday afternoon, to the point where he was having problems simply swinging in the cage.
"I was trying to go yesterday," Polanco said Wednesday afternoon, "But I was hitting, and [it hurt] every time I went to swing."
Polanco was diagnosed with patella tendinitis, and was out of the lineup, replaced by at second base by Ramon Santiago. Manager Jim Leyland had already slated Polanco to rest on Wednesday, ahead of Thursday's off-day, and that plan remained intact. Polanco's knee was already feeling somewhat better on Wednesday, though it was still sore.
Leyland said after Wednesday's game that he wasn't sure whether Polanco would ready to go on Friday.
It's a rare knee issue for a player whose knees have been solid over the years. He missed time with a pinched nerve in his back in April, had stints on the disabled list with a separated left shoulder two years ago and suffered a strained left hamstring in 2005. Other than that, he has been quite durable as he ages into his 30s.
Santiago filled in for Polanco again on Wednesday, batting second in the order after his two-hit game Tuesday night.
Jason Beck is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.