McNabb said Tuesday that the ankle wouldn't keep him from starting. "Yes, I will be starting this weekend," he told ESPN980. "And I look forward to it."
McNabb said the injury isn't classified as a high ankle sprain -- the more severe type that has more significant ligament damage and a longer recovery time -- but he said it's "very close to it." He said he's receiving multiple treatments each day.
"Is it 100 percent? No. ... But it's getting better," he said.
The Redskins listed four other players as questionable for Sunday's game: offensive tackle Jamaal Brown (hip), linebacker Andre Carter (illness), linebacker Perry Riley (foot) and fullback Mike Sellers (knee). Safety Kareem Moore (knee) was listed as probable.
As expected, the Cowboys ruled out guard Kyle Kosier (knee) and offensive tackle Marc Colombo (knee).
Alex Barron will start in place of Colombo at right tackle, and Montrae Holland will fill in for Kosier at left guard. Barron and Holland have seen action in those spots since the starters went down with knee injuries a few days apart in mid-August.
Colombo was expected back by this week. Kosier could miss up to the first three games.
The Associated Press contributed to this report.