Harper started feeling sick Thursday night and began taking some medicine, and team doctors gave him a shot Friday morning. He was still sniffling during his media rounds before taking the floor for the Tigers' open practice ahead of their semifinal date with Virginia.
Tigers coach Bruce Pearl said Harper wouldn't be 100 percent if the game were on Friday but that the guard should be fine by Saturday.
"We've got a bunch of guys that are sniffling and hacking and coughing, but we don't play today," Pearl said.
Fellow guard Bryce Brown felt the worst of it on Thursday but was on the rebound Friday.
The flu bug swept through North Carolina last weekend in Kansas City, where the Tigers knocked off the Tar Heels in the regional semifinal. It's unclear whether Harper may have gotten the same bug.
Harper is averaging 15.4 points and 5.4 assists per game.
The Associated Press contributed to this story.