ARLINGTON, Texas -- Injuries keep mounting for the Washington Redskins.
Coach Jim Zorn said Portis, out since Nov. 8 because of a concussion, will not play next week against the Philadelphia Eagles.
Betts, Portis' backup, sustained damage to the MCL in his left knee midway through the first quarter of Washington's 7-6 loss to Dallas. Zorn said Betts will have an MRI to determine the severity of the injury.
Right guard Chad Rinehart fractured his right leg early in the third quarter. Rinehart was taken off the field on a motorized cart with his lower leg in a brace after it was rolled on by Cowboys linebacker Anthony Spencer.
"It's just one of those things where someone else gets an opportunity," linebacker London Fletcher said. "They aren't going to cancel the game in Philadelphia because the Redskins aren't healthy."
Washington has shuffled its lineup throughout the season because of multiple injuries to key players.
"Everyone is trying to stay positive," Washington quarterback Jason Campbell said. "Even though we've lost a lot of guys, no one got down on themselves."
Portis visited a specialist in Pittsburgh on Friday and has not practiced since he was injured in a helmet-to-helmet hit.
Betts has been filling in for Portis and apparently got hurt on a hard tackle by Bradie James at the end of a 2-yard gain. He finished with 5 yards on four carries.
Without their top two runners, the Redskins' Rock Cartwright rushed for 67 yards and caught seven passes for 73 yards. Cartwright, who had only 17 carries coming into the game, sounded like he was going to get more action in the coming weeks.
"I have an opportunity," Cartwright said. "All I can do is take advantage of the workload and play on Sundays."
"We've got a big game next week," Zorn said. "We're going to look at our roster, patch it up and go again."