Bench coach Rob Thomson will manage the Yankees instead as the club opens a four-game weekend wraparound series with the Rays. The Yankees said that Girardi had slept most of the afternoon and is under heavy medication to battle a high fever.
"He's been behind closed doors because we don't want to affect everybody else," Thomson said. "He's doing fine."
Thomson said that he spoke with Girardi earlier in the day, but had not expected that Girardi would be unavailable. Thomson indicated he believed this would just be a one-day fill-in assignment.
"I think it got a little bit worse as the day went on," Thomson said. "He wants to be out there, no question. If he's not going to make the bell, he's not feeling too good."
Thomson, 44, is in his first season as the Yankees' bench coach and his 19th as a member of the Yankees' organization. His lengthy service also included a stint managing the Oneonta Yankees of the New York-Penn League in 1995, piloting the club to a 34-41 finish. Thomson said he also managed for one year in the Australian Winter League.
Girardi said late Thursday that he was beginning to suffer from effects of the ailment. His eyes watered during a postgame session with reporters and he was seen coughing in the clubhouse before leaving the stadium. With Girardi up the tunnel and resting on a couch, Thomson said he will lean on his coaching staff, some of whom also have prior managerial experience.
"If we need something, he'll be on hand," Thomson said. "We're going to be fine."
First-base coach Tony Pena won the American League Manager of the Year Award with the Royals in 2003, and was a candidate in the Yankees' interview process last winter, while hitting coach Kevin Long shared a Minor League managing award in 1999 with the Spokane Indians.
"Managing, to me, is just communicating with the coaches," Thomson said. "It's kind of a team effort anyway, whether it's me managing or Joe or anybody else. It'll be a lot of fun."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.