Richmond will be without Mykelti Lefau for the remainder of the 2024 season after scans confirmed a ruptured anterior cruciate ligament in his right knee.
The promising key forward had left the ground during the final quarter of the Tigers' 30-point loss to Geelong after landing awkwardly in a marking contest.
"Football can be a cruel game sometimes, and for Mykelti, who has been in terrific form, this is an unfortunate way for his debut season to finish," Richmond footy performance manager Tim Livingstone said.
"Mykelti has not put a foot wrong since he joined our AFL program in the pre-season."