Witten tried to return after injuring his ribs last weekend against Tampa Bay, but he eventually sat out most of the second half. He could wear added protection against the Giants, according to a posting Tuesday on the team's Web site.
The Cowboys were already without Pro Bowl quarterback Tony Romo when Witten, the NFL leader in yards (549) and catches (46) among tight ends, got hurt late in the first quarter.
Rookie Martellus Bennett and Tony Curtis back up Witten.
Cornerback Anthony Henry tore his quadriceps against the Buccaneers, but the Cowboys are optimistic rest and treatment will be enough for him to play Sunday, according to the Web site. If Henry can't play, Orlando Scandrick would start opposite fellow rookie Mike Jenkins.