The 23-year-old was on the bench for the final, which Senegal won 1-0, before coming on in extra time as the sixth substitute. He lasted seven minutes before going off injured, leaving Walid Regragui's side to finish the match with 10 men.
"Tests carried out on the player have unfortunately confirmed a serious injury. Hamza Igamane has indeed suffered a rupture of the anterior cruciate ligament in his right knee," Lille said in a statement.
"Hamza will be unavailable for several months," it added, with the injury coming five months before the 2026 World Cup, where Morocco will face Brazil, Scotland and Haiti in Group C.
Igamane, who joined Lille from Rangers in the summer, has scored nine goals in 21 games for the French side in all competitions.