Witten starts despite being bothered this week by a sprained left foot sustained in Sunday's 7-6 victory over Washington.
Cowboys safety Ken Hamlin (right ankle) and offensive tackle Marc Colombo (broken left leg) are both inactive and will miss their second straight game.
The Raiders placed linebacker Jon Alston on injured reserve, ending his season after two concussions. Sam Williams will replace him in the starting lineup for the second consecutive game, and rookie Slade Norris was signed from the practice squad but listed as inactive.
Oakland defensive ends Richard Seymour (lower back strain) and Greg Ellis (knee, shoulder) are active. Ellis played the first 11 seasons of his career for Dallas before signing with Oakland this summer.
The Associated Press contributed to this report