Redskins quarterback Jason Campbell knows that they'll be additional pressure on him against the Cowboys this weekend if running back Clinton Portis isn't able to play. "If Clinton can't play we all still have to go out there and play hard," Campbell said. "You do that anyway because of the nature of the game. Clinton is a playmaker and we also use him in our pass blocking schemes, so if Clinton can?t go hopefully Ladell (Betts) can go and Shaun (Alexander) has been preparing himself for the opportunity." Portis admitted earlier this week that he sprained his right MCL against the Steelers less than two weeks ago. "It?s different," Campbell said of the pressure he'll face should Portis sit. "You have the leading rusher back there and a guy who?s so versatile in our offense. It definitely adds a dimension because people have to respect our run game and it gives you the opportunity to utilize your whole offense. You don?t want to have to get one-dimensional, if he can?t go, I?m pretty sure we will still do good things rushing the ball, but just having him back there adds another dimension."