ASHBURN, Va. -- Five observations on the Washington Redskins' defense following Sunday's 34-23 win over the Dallas Cowboys:

It’s not that the Redskins can’t withstand the loss of safety Kyshoen Jarrett. They’ve overcome numerous injuries this season. But losing him will hurt. Jeron Johnson can help as a third safety -- heck, he was brought to Washington to challenge for a starting job and essentially has been beaten out by a number of players. Jarrett provided versatility and toughness (Johnson gives them the latter, too). In the Dallas game, Jarrett again showed how aggressive he is vs. the run. He doesn’t always make the play in the backfield -- he missed Darren McFadden on one run -- but he creates problems. Jarrett played smart and disciplined; on a fake end-around (the play in which Ryan Kerrigan sacked Kellen Moore), Jarrett was positioned properly on the outside, staying where he should. Jarrett’s size -- he’s generously listed at 5-foot-10 -- might limit his role to just that of a third safety even in the future. But if that’s all he becomes, he’ll still be a strong contributor in many ways.

Rookie linebacker Preston Smith faced a strong test in Cowboys left tackle Tyron Smith, one of the best in the league at his position. Early on it appeared Preston Smith was too worried with trying to fool Tyron Smith and was thinking too much. It led to ineffective rushes. Tyron Smith is way too patient to fall for any fake steps, especially when they’re not at a fast pace. As the game wore on, Preston Smith was a little more effective and it typically stemmed from just going at the Dallas tackle. He didn’t win a whole lot, but he at least pinched the pocket more and that forced Moore to step into pressure. On two sacks, Preston Smith pinched the edge, helping create a tough pocket.

Before Sunday, Will Compton's last interception occurred in his final game at Nebraska, a pick-six. Sunday, he intercepted his first pass in the NFL after dropping into a Tampa-2 coverage. Compton credited Keenan Robinson with forcing an overthrow because of his underneath coverage on the tight end. Robinson had overrun the spot a little bit before the throw, but it was still a tight window because corner Dashaun Phillips had dropped deep enough. “I stuck my arms out and the ball took forever to get there,” Compton said. “I was nervous. I was like, can you catch this? And I was like, man I have to make this play. It was a trash catch. [Linebackers coach Kirk Olivadotti] said he heard from the sideline like it hit my forearm. I brought it in and was like, damn I got one. I was smiling and happy as can be running. I was laughing and like, wooooooo."

Nose tackle Terrance Knighton had played well the previous week and he still flashed in the run game at times Sunday. But Knighton also has a tendency to get too upright; sometimes it leads to big plays (see Philadelphia), but if the center can react well then it leads to a good block. I have a feeling Green Bay will try to run the ball a little more Sunday, which means Knighton will have to be on his game to make the impact Washington hoped he would this season. He said this is when he plays his best ball.