The San Francisco 49ers placed wide receiver Kyle Williams and running back Kendall Hunter on injured reserve Wednesday.
Both players suffered their season-ending injuries on the same play during Sunday's win over the New Orleans Saints.
Williams, who caught 14 passes for 212 yards and one touchdown this season and was also an option to return kicks on special teams, tore the anterior cruciate ligament in his left knee.
Hunter, a reliable backup to running back Frank Gore, suffered a torn Achilles tendon. The second-year back had carried the ball 72 times for 371 yards and two scores through the first 11 games for the NFC West leaders.
The club made three other moves on Wednesday, adding running back Jewel Hampton to the active roster, signing wide receiver Chad Hall to the practice squad and waiving safety Eddie Whitley from the practice squad.