Quarterback Donovan McNabb did not practice on Monday due to an ankle injury.

McNabb was seen wearing a protective boot in the morning. In the afternoon, he was wearing a protective cast around the ankle as he watched practice from the sidelines.

McNabb appeared to be in good spirits, though. He joked with teammates from the sidelines as they went through warm-ups and stretching.

Head coach Mike Shanahan said he was unsure of McNabb's availability for practice this week. His availability for this Friday night's preseason game is also uncertain.

"We are just going to get as much treatment as we can and try to get him ready as quick as we can," Shanahan said. "Time will tell."

Rex Grossman, John Beck and Richard Bartel took reps at quarterback during practice.

Grossman would likely start against the Jets if McNabb is unable to play.

McNabb suffered the injury in last Saturday's preseason game against the Baltimore Ravens.

He played the entire first half and completed 11-of-26 passes for 206 yards and one interception.

He was blitzed several times by an aggressive Ravens defense and sacked once by linebacker Terrell Suggs.

In the Redskins' two preseason games, McNabb has completed 16-of-34 passes for 264 yards, one touchdown and one interception.