The Cowboys have placed cornerback Orlando Scandrick on season-ending injured reserve and signed defensive tackle Rob Callaway off the practice squad.
The addition of Callaway came after nose tackle Josh Brent was arrested on an intoxication manslaughter charge Saturday in the death of teammate Jerry Brown in a car accident. Brown, a linebacker, was on the practice squad.
Police in the Dallas suburb of Irving say Brent was speeding when the vehicle struck a curb and flipped. He wasn't in Cincinnati for Sunday's game against the Bengals.
Scandrick, the primary defensive back in nickel coverage, injured his left hand and wrist in the Thanksgiving loss to Washington and later had surgery.
Callaway signed as undrafted free agent with Detroit two years ago, and the Cowboys picked him up last season.