ALLEN PARK -- The Detroit Lions traded Quandre Diggs partly because they believed their secondary was deep enough to weather the loss without interruption.

That thinking is about to be seriously tested.

Tracy Walker, Detroit’s other starting safety, is not expected to play Sunday against the Oakland Raiders because of a knee injury. He suffered the injury in the third quarter of last week’s win against the New York Giants, Detroit’s first game without Diggs.

That forced Tavon Wilson and Will Harris into full-time roles, and then Wilson missed stretches of the second half with an injury of his own, forcing C.J. Moore -- an undrafted rookie who usually plays exclusively on special teams -- into full-time jobs. Miles Killebrew, a former safety who moved to linebacker and hadn’t played a defensive snap since 2017, also saw time back there against New York.

“We’re always ready to adjust based on whoever’s out there,” coach Matt Patricia said before practice on Friday. "Sometimes safety depth isn’t necessarily just from the safeties. In those situations, we do what we can to kind of overlap those situations if (Walker) can’t play. But we’ll see as we go here and see how he feels through the course of today and tomorrow.”

Other injured players like running back Tra Carson, cornerback Darius Slay, defensive tackle Snacks Harrison and offensive lineman Graham Glasgow were all practicing on Friday. Game designations are due at 4 p.m. today.