FRISCO, Texas -- Dallas Cowboys running back Ezekiel Elliott had an MRI after last week's win against the New Orleans Saints that showed his ailing right knee is "healing up and going in the right direction," he said.

Elliott was officially a full participant in Wednesday's practice and will play Sunday in a pivotal NFC East matchup against the Washington Football Team at FedEx Field.

"It's football, you're never going to be 100%; might be 100% the first day of camp," Elliott said. "It's a tough game. But, yeah, I take a lot of pride in being out there. You are going have to drag me off the field."

Elliott, who has missed just one game to injury in his career, did not divulge the nature of the injury but said it is not a bone bruise that has bothered him since the Week 4 win against the Carolina Panthers. He said he would not require postseason surgery.

"Playing on it is not making it worse," Elliott said.

And that might be why the Cowboys have opted not to sit Elliott for added rest, although they have cut back on his snaps. The Cowboys have been conservative with the returns of players from injury, most notably Dak Prescott (calf) and Tyron Smith (ankle). Elliott has continued to play even as his effectiveness has waned. In the past six games, Elliott has averaged 40.6 yards a game, has not topped 51 yards and has had two carries of 10 or more yards.

"You're taking all the information. You've got to remember, too, now, you're out there for pregame, pre-practice; and particularly Zeke and Dak, just themselves, these guys do a lot of extra, a lot of extra work both here at the Star and with outside resources," coach Mike McCarthy said. "There's a lot that goes into it. There's a lot of information that's utilized. At the end of the day, you trust the process between the player and the training staff."

Before Wednesday's practice, Elliott rode a stationary bicycle to get loose. His backup, Tony Pollard, did some resistance training off to the side during the portion of practice open to the media; he has a foot injury and did not practice.

Pollard had a 58-yard touchdown run against the Saints a week after a 100-yard kickoff return for a score against the Las Vegas Raiders on Thanksgiving. He has a career-high 602 yards on 107 carries and two touchdowns.

Although both running backs will be available against Washington, the Cowboys added veteran Ito Smith to the practice squad Wednesday. Corey Clement, who has 20 yards on nine carries, is the only other tailback on the 53-man roster.

"I think it is important," Elliott said of playing through the injury. "It's late season, getting a little nicked up. Just have to fight through it and figure it out."