Right tackle Tyler Polumbus (74) and the Redskins’ offensive line break the huddle against Philadelphia last month. (John McDonnell/The Washington Post)

Redskins coach Mike Shanahan said that right tackle Tyler Polumbus missed another practice while suffering from concussion related symptoms.

Shanahan said Polumbus showed some improvement when he was evaluated today, but it wasn’t enough for him to practice.

Polumbus practiced in a limited capacity twice last week, but was held out of the game on Sunday. Shanahan didn’t know whether Polumbus suffered a setback before Wednesday’s session, but said that he could not practice. 

Receiver Dezmon Briscoe also missed practice because he missed his flight back to the D.C. area. Shanahan said the mistake will “cost him a little cash.”

Linebacker London Fletcher (ankle) and safety DeJon Gomes (knee) were both limited in practice. Shanahan said that he didn’t know about Gomes’ availability for Sunday yet.

Shanahan said Sunday’s contest against the Cowboys”is a game you remember all your life. … This is why you play the game, for moments like this.”

Shanahan praised the poise that quarterback Robert Griffin III continues to display. Shanahan said the quarterback’s preparation and work ethic is the key to his success.

Shanahan said he thinks the Redskins could qualify three players for the Pro Bowl, but declined to say who they might be. Asked about the play of Lorenzo Alexander later, Shanahan said he would be surprised if his special teams captain didn’t make the Pro Bowl.