ATLANTA | Already missing three key players from their offense, the Washington Redskins could ill-afford to be without yet another player - let alone Clinton Portis. But that's exactly what they had to deal with Sunday after Portis left early in the 31-17 loss to the Atlanta Falcons with a concussion. The running back became the Redskins' fourth starter - and third 2008 Pro Bowl pick - to be sidelined. Portis, the NFL's leading rusher a year earlier, suffered a concussion when h...