Giese was examined by Dr. Chris Ahmad on Thursday at New York Presbyterian Hospital. The Yankees will make a corresponding move before opening a three-game series with the Royals on Friday at Yankee Stadium.
A 31-year-old rookie, Giese threw 15 pitches in relief of starter Darrell Rasner on Wednesday before exiting with what he described as a feeling similar to a tetanus shot in his shoulder or a deep bruise from repeated punching.
Giese opened the sixth inning by allowing a leadoff single to Joe Mauer before walking both Justin Morneau and Jason Kubel. He then left the field with assistant trainer Steve Donohue.
"The shoulder just stiffened up on me while I was trying to face Mauer," Giese said on Wednesday. "I was trying to overthrow. It just got progressively worse and worse the more pitches I threw."
Giese had been scheduled to start on Tuesday in Toronto, where the Yankees are set to open a three-game series with the Blue Jays. Rasner, who allowed three runs (two earned) in five innings against Minnesota on Wednesday, could make that start.
Giese was 1-3 with a 2.58 ERA in 15 games (three starts) for the Yankees this season after beginning the year at Triple-A Scranton/Wilkes-Barre. He threw 83 pitches in a start on Saturday in Anaheim and limited the Angels to one run over six innings, but he said on Wednesday that he did not believe coming back on short rest had affected him.
"You never know," Giese said. "I've done it before, so it wasn't anything new for me. I don't think that played into it."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.