"I'm a better player in the sense that I understand the defense a little bit more," Washington said. "I understand what (assistant head coach/defense Gregg Williams) wants out of me. When I mess up, I already know it and have gone over it about 20 times in my head before (linebackers coach Dale Lindsey) or coach Williams tells me about it.
"You're either getting better or getting worse," Washington added. "I'm just trying to keep improving. I still have a ways to go. I want to be better as an individual player, but I also want to make the team better."
Washington has done that. His 97 tackles are on pace to match last season's total. He has already matched his 4.5 sacks of 2004. Only middle linebacker Lemar Marshall has more tackles (103), and Washington leads the Redskins in tackles for loss, sacks and forced fumbles. And the Redskins have won six games, as many as they did in all of 2004.
"Without Marcus, we'd be a very average to mediocre defense," Williams said. "He's a pro pro. Any time you mention anything to him about a weakness, Marcus takes it personal. When he first came here, (if you looked for a negative) you said he's probably deficient in coverage. He's improved so much."
And Washington set the tone for the defense's best day of the season in its most critical game to date, sacking Rams quarterback Ryan Fitzpatrick for a 10-yard loss at the 1-yard line on the Rams' first third down of last week's 24-9 Redskins victory. Two and a half of Washington's sacks have come in the past two games.
"You have to play your best football in November and, especially, December if you want to be a playoff team," Washington said. "I'm really just giving it everything I've got. You never know which play is going to be that play where you can make a difference."
--WR Santana Moss missed practice Thursday after straining a hamstring early in Wednesday's session. The Redskins still expect him to play Sunday at Arizona.
--LB LaVar Arrington didn't practice again Thursday because of the thigh bruise he suffered last Sunday at St. Louis. He is questionable for Sunday. Warrick Holdman likely would start if Arrington can't play.
--DT Joe Salave'a took some individual work Thursday and likely will miss a second straight game with plantar fasciitis in his left foot.
--SS Ryan Clark returned to practice Thursday after missing Wednesday because of the ankle he sprained last Sunday in St. Louis. Clark is probable.
--DT Cornelius Griffin returned to practice Thursday after resting his sore hip flexor on Wednesday. Griffin is probable.
--DT Cedric Killings was on the field Thursday for the first time since pulling a groin muscle last Thursday, but he remains questionable for the Cardinals.
--T Chris Samuels returned to practice Thursday after resting his tender knee on Wednesday. Samuels should start at Arizona.--WR James Thrash took some individual work Thursday but isn't expected to play for a third straight game because of a pulled hamstring.