Kansas State officials told Star that Pullen had been suffering from flu-like symptoms and a high fever, but they expect him to recover in time to play against Utah State on Thursday night in the second round of the NCAA tournament.
Associate athletic director Casey Scott said Pullen asked to practice Wednesday, but coach Frank Martin told him to rest at the hotel.
Teammates said Pullen was suffering from food poisoning.
"It was from something he ate last night, a cheeseburger or something like that," sophomore Jordan Henriquez-Roberts told the Star. "But he's going to be all right and he's going to go tomorrow. I know Jake ... he's going to give his all tomorrow whether he's 100 percent or not."
Pullen leads the Wildcats in scoring with 19.5 points a game. Kansas State has the last scheduled tipoff Thursday at 9:57 p.m. ET.