The Pittsburgh Tribune-Review reported the injury was determined when X-rays taken were taken at a hospital Sunday.
The X-rays revealed a fractured fifth metatarsal in the junior's left foot and surgery will be performed Monday by Drs. Freddie Fu and Robin West of the University of Pittsburgh Medical Center.
Fields, who was injured during Saturday's 80-55 upset loss at Dayton, is the second major personnel loss for the sixth-ranked Panthers this month. They lost senior guard Mike Cook to a torn left knee ligament Dec. 21 in the Panthers' 65-64 overtime victory against Duke.
Coach Jamie Dixon is left with nine healthy scholarship players following Fields' loss.
Also, reserve forward Austin Wallace suffered a season-ending knee injury Dec. 7.