Head coach Kyle Shanahan told reporters Monday that wide receiver Brandon Aiyuk and left tackle Trent Williams will miss the contest with a high ankle sprain and sprained elbow, respectively, ending their seasons. Williams will not need surgery, per Shanahan.
This is another setback for Williams, who missed the entire 2019 campaign when he was on Washington.
Williams was impressive in a bounce-back effort this year for the 49ers, though, and was selected to the eighth Pro Bowl of his career.
Few teams have had worse injury luck than San Francisco this season. Aiyuk sat out Week 1 with a hamstring injury. The reigning NFC champions also lost key defenders Nick Bosa and Solomon Thomas for the year because of torn ACLs.
Cornerback Richard Sherman was placed on injured reserve after Week 1, wideout Deebo Samuel began the year on injured reserve, and star tight end George Kittle (broken foot) and starting quarterback Jimmy Garoppolo (sprained ankle) missed time this season. No. 1 running back Raheem Mostert was also in and out of the lineup because of injuries.
The 49ers selected Aiyuk with the 25th overall pick in the 2020 NFL draft and traded up in the first round to get him. He was expected to play a pivotal role in head coach Kyle Shanahan's offense after Emmanuel Sanders left to join the New Orleans Saints in free agency.
Since making his debut in Week 3, Aiyuk has racked up 748 yards receiving, 77 rushing yards and seven total touchdowns.
Aiyuk was a big-play machine at Arizona State in 2019. He led the Pac-12 with 18.3 yards per reception, ranked second with 1,192 receiving yards and tied for fourth with eight touchdown catches.
Kendrick Bourne and Richie James will move into a more prominent role for the 49ers as they look to finish the season with a win.