San Francisco 49ers wide receiver Brandon Aiyuk sustained a potentially season-ending knee injury during the team's 28-18 loss to the Kansas City Chiefs. Aiyuk, who recently signed a $120 million contract extension, was carted off the field after his knee was hit awkwardly by Chiefs defenders, and the team fears he has torn his ACL, pending further medical examination. This injury is a significant setback for the 49ers, who are already dealing with other key absences, including Deebo Samuel due to illness and Christian McCaffrey. Aiyuk's injury compounds the 49ers' struggles, as they now hold a 3-4 record amid a season plagued by injuries and inconsistent performances. The 49ers hope to bounce back in their next game against the well-rested Dallas Cowboys.