Eric Mortensen, BYU's promising freshman running back and kick returner, will undergo surgery this weekend to repair a knee injury he suffered during Thursday's practice.

According to trainer George Curtis, Mortensen tore the anterior cruciate ligament and a couple of cartilages in one knee. "Both can be repaired," said Curtis, "so doctors will operate on Sunday."Mortensen will be sidelined for the remainder of the season. He ranks fourth in the nation in kickoff returns with a 28.43 average. Against Utah State he returned a kickoff 100 yards for a touchdown. Mortensen also has played running back in a reserve role and has rushed for 116 yards and 2 touchdowns on just 20 carries.

According to Curtis, the knee injury was a fluke. "He had no previous injury," said Curtis. "He was running a pass pattern. He jumped in the air, caught the ball and, as he landed, decided to change direction. The knee buckled and he fell down."