Jason Hammel will start the series opener on Friday in Toronto. Norris will be shut down and allow the elbow to "quiet down," said manager Buck Showalter.
"How do I put it? Elbow," Showalter said when asked why the Orioles changed starters. "Had a work day. It barked a little bit in Arizona but resolved itself real well. And then the work day today wasn't as comfortable as we would have liked it to have been, so we're going to skip him and see if we can clean that up and put Ham there. Ham will pitch there. I kept him out of the game tonight.
"We'll see how it develops. We want to back off and treat it. You're always working on your next start and there's some things that guys do. I think talking to Bud and to trainers, I think it would be best to stay away from all the work that starting pitchers do to get ready for their fifth day and just let it quiet down.
"It managed itself well the last time, so we want to get back to that. I think you'll see him pitch again for us."
Norris is 4-2 with a 4.67 ERA in nine games, including eight starts, since the Orioles acquired him from the Astros on July 31.
It's possible that Norris could return to the rotation while the Orioles are in Boston for a series that begins on Tuesday.
Showalter described the elbow issue as "discomfort."
"But it's nothing that Bud seemed alarmed with other than he agreed after his work day today it would probably be best to just let it quiet down," Showalter said. "We're lucky to have Ham there."