Allen will undergo surgery to repair his dislocated/fractured left ankle and won't return this season, Ian Rapoport of NFL Network reports.
Allen's injury isn't as bad as it was initially feared, but he'll need surgery to repair the dislocation, which is expected to require a four-month recovery. Alex Smith will start under center Week 10 against the Lions, while 2019 first-rounder Dwayne Haskins serves as the backup for the time being. Allen's final stat line for the season reads 610 passing yards, four touchdowns and an interception, plus 26 yards and a touchdown on the ground. The 24-year-old quarterback is expected to make a full recovery for the 2021 season, and he'll be an exclusive-rights free agent in March.