The NFL's second-leading rusher left Redskins Park during practice, wearing a gray hooded sweat shirt and burgundy sweat pants as he stepped into his Maserati.
"I was hoping today that there would be a little more optimism, and there's not," coach Jim Zorn said. "He's still questionable. I would say there's no change today. I was looking for another jump, but there wasn't."
Portis sprained his left knee in the 23-6 loss to the Pittsburgh Steelers before last week's bye.
With Portis ailing, Ladell Betts appears set to start Sunday. Betts has missed the last three games with a sprained knee, but he was on the field in steady rain for Thursday's practice.
"Betts looked good," Zorn said. "He's got a brace on, but made some cuts. That was encouraging."
Shaun Alexander would start if both Portis and Betts are unable to play.