Louisville coach Rick Pitino said Mathiang broke the fifth metatarsal in his foot and that it would require a screw to be inserted.
Pitino called the 6-foot-10 junior ''the best physical player'' on the team.
Mathiang has more experience than anyone on the No. 19 Cardinals, serving as one of three captains alongside graduate transfers Trey Lewis and Damion Lee. He scored three points and had five rebounds in 21 minutes before the injury.
Mathiang is averaging 7.1 points and 5.7 rebounds and started in two of Louisville's 10 outings this season. He had his first career double-double this season with 17 points and 13 rebounds in a win against Saint. Louis.
Born in Sudan, Mathiang lived in Melbourne, Australia, before moving to the U.S. while in high school. He played for Australia's World University Games team, leading the team in rebounding.