Walker was released by the Lions on Tuesday, Jeremy Fowler of ESPN.com reports.

Walker registered six tackles (three solo) including a sack in Monday's 26-14 win over the Raiders.

Walker had seven tackles (five solo) in Sunday's 38-6 loss to the Ravens.

Walker will start Sunday against the Falcons, Kyle Meinke of MLive.com reports.

Walker appears to have lost his starting job after Brian Branch's recent promotion to the first-team defense, Kyle Meinke of MLive.com reports.

Walker (Achilles) worked with Detroit's first-team defense Saturday, Benjamin Raven of MLive reports.

Walker (Achilles) was a partial participant during OTAs and expects full clearance for training camp, Tim Twentyman of the Lions' official site reports.

Walker recently posted videos on social media of himself aggressively going through an agility drill, Woodward Sports Network reports.

Walker (Achilles) recently suggested via his personal Twitter account that he will be ready for the Lions' offseason training program this spring.

The Lions placed Walker (Achilles) on injured reserve Tuesday.