Brandon Aiyuk's season is over.

The San Francisco 49ers wide receiver suffered a season-ending knee injury in Sunday's 28-18 loss to the Kansas City Chiefs, tests confirmed Monday, according to NFL Network's Ian Rapoport. Aiyuk has a torn ACL and ACL, and his knee may show further damage. He will undergo surgery in the near future.

Aiyuk caught a pass across the middle of the field late in the first half of Sunday's game at Levi's Stadium, but his knee gave way badly when he was hit and tripped. Ayiuk remained on the field for quite a while before finally leaving the medical tent. He was eventually dragged to the locker room and ejected from the game.

49ers head coach Kyle Shanahan said after the game that the team feared he had suffered an ACL injury.

Aiyuk lasted most of the offseason and preseason this fall while searching for a new long-term contract with the organization. He ultimately signed a four-year, $120 million contract to remain in San Francisco.

Aiyuk will finish the season with 374 yards and no touchdowns on 25 catches. All of these numbers are career lows for the 26-year-old, who the 49ers first selected with the No. 25 overall pick in the 2020 NFL Draft out of Arizona State. Aiyuk threw for a career-high 1,342 yards and seven touchdowns last season while leading the 49ers to the Super Bowl.

Aiyuk's injury is just the latest the 49ers' offense has dealt with this season. Star running back Christian McCaffrey still hasn't seen the field because of a calf and Achilles tendon injury, and Deebo Samuel only appeared in a few moments on Sunday before leaving the game due to illness. Rookie wide receiver Ricky Pearsall made his NFL debut in Sunday's loss after missing the first six games of the year after also being shot in the chest earlier this fall.

After Sunday's loss, the 49ers fell to 3-4 on the season. They will host the Dallas Cowboys next week.