Walker has been diagnosed with an ACL tear, Jeremy Fowler of ESPN.com reports.
As suspected, Walker will need surgery and is set to miss the entire season. Coming off a 5.5-sack rookie campaign, Walker was expected to start at outside linebacker for the Falcons this year. With fellow pass rusher and 2025 draft pick James Pearce facing serious legal issues, Atlanta's pass rush looks to be in poor shape with the season just five weeks away.