Starting safety J.J. Wilcox injured his knee during Thursday's practice and is expected to miss Sunday's game against the Lions. Wilcox has started the past five games, making 28 tackles this season.
Undrafted rookie Jeff Heath likely will start at strong safety if Wilcox can't play. Heath played 24 snaps last week, getting in plays at both safety spots.
Starting cornerback Morris Claiborne missed practice with an illness.
Receiver Dez Bryant (hamstring/wrist) returned to a full practice after being limited Wednesday, but receiver Miles Austin (hamstring) remained limited for a second day in a row. Defensive end DeMarcus Ware (thigh) rehabbed on the side during practice. Linebacker DeVonte Holloman (neck) also missed practice.
Defensive tackle Nick Hayden missed his second day of practice, but he said his back spasms have subsided and he hopes to practice Friday. Defensive tackle Jason Hatcher (neck), running back DeMarco Murray (knee), defensive end George Selvie (shoulder) and running back Lance Dunbar (hamstring) all were limited.
Offensive guard Ron Leary, who missed Wednesday's practice with a sore knee, was a full particpant as was receiver Dwayne Harris (hip).
-- Charean Williams