"Tommy's had an ingrown toenail that he's had a cut on," manager Buck Showalter said. "I just want to give him a couple extra days and get him back to 100 percent. He'll tell you that he is, but we had an opportunity and we'll see if we can give him a couple extra days there."
With Thursday's off-day, the Orioles' arms will each get an extra day's rest, and Hunter -- who has also been one of several players under the weather -- will now start the series finale on Sunday afternoon.
"He threw today, he's fine," Showalter said of Hunter, who is 2-1 with a 4.26 ERA. "He feels good. I just thought we weren't going to have this opportunity much up north. We'll try to fresh up his everything a little bit."
Wei-Yin Chen (2-0, 2.22 ERA) will start Friday's series opener, facing Boston for the first time in his career.