Washington Redskins running back Clinton Portis was at the University of Pittsburgh Medical Center on Friday to have his concussion evaluated.
Portis saw the same doctors who examined Philadelphia Eagles running back Brian Westbrook, who has suffered two concussions in the last month. Portis was hurt two weeks ago against the Atlanta Falcons. He didn't play last weekend against the Denver Broncos and has been ruled out for Sunday's game against the Dallas Cowboys.
"I want to be involved with those conversations, not so much to see 'how fast can we get him back,' but just to make sure the young man is improving and getting better."
Portis gave his own update via Twitter: "Hey fans! Trying to get healthy to finish the season strong, want to make sure there aren't lingering affects before returning to the field."
Redskins defensive tackle Albert Haynesworth is questionable to play Sunday because of a sprained left ankle. Haynesworth was unable to practice this week, but he tested his ankle on a treadmill Friday.
Zorn said Haynesworth's status remains a game-time decision, although a league source told NFL.com's Steve Wyche on Friday that the defensive lineman probably will not be healed in time to play.
A team source told NFL Network's Jason La Canfora on Thursday that the Redskins are discussing dressing an extra defensive tackle -- Anthony Montomery -- for the game at Dallas. Montgomery has been a starter in previous seasons but has yet to play in 2009.
The Associated Press contributed to this report.