Villanova guard Collin Gillespie left Wednesday's game against No. 14 Creighton with a knee injury and did not return.
Gillespie is scheduled to have an MRI on Thursday.
"It's serious. We don't know exactly what it is, but it's serious," Villanova head coach Jay Wright told Fox Sports after his team's 72-60 win. "For him to not be able to come back and the doc say he's definitely out, you know it's pretty serious."
The No. 10 Wildcats managed to hold on and clinch the Big East regular-season title without Gillespie in the second half. It's not yet clear how long they'll be without their senior guard.
Gillespie has put together a strong campaign for Villanova, ranking top 10 in the Big East in both points and assists to help the Wildcats post a 15-4 record. He's averaging 14.4 points, 4.7 assists, and 3.3 rebounds per game while shooting 42% from the field.