Rick Pitino returned and resumed his coaching duties Thursday after a two-day medical leave.
Pitino, 51, was tested at the Cleveland Clinic on Tuesday and Wednesday to determine the cause of a "urological pain" that has persisted in his left side for months.
Assistant coach Kevin Willard substituted for Pitino in fourth-ranked Louisville's 64-48 win over Houston on Wednesday night.
Pitino was not available for comment Thursday. He is expected to discuss his condition at a news conference this afternoon.
The Cardinals play Marquette on Saturday at Freedom Hall.
OBITUARY: Russell "Sox" Walseth, who holds the Colorado record for coaching wins, died Wednesday at his Boulder, Colo., home two years after contracting cancer. He was 77. Mr. Walseth was 261-245 and won three Big Eight titles with the Buffaloes from 1956-76.