A quick look back at Washington's 22-21 preseason opening win over Tennessee on Thursday:

Kirk Cousins continues to mature at quarterback. What he showed Thursday were traits similar to what he revealed last summer, too. Poise in the pocket. Toughness. Decisive throws. Only this time, he can now mix in knowledge of the offense and how to read an NFL defense to go with those traits. It led to a good opening night for Cousins and the Redskins’ offense. Cousins completed 6 of 7 passes for 52 yards and a touchdown. You don’t want to go overboard, partly because even in practice Cousins still throws his share of interceptions. But his mind seems to slow down amid chaos and that helps give him a chance for continued growth.

Cousins does an excellent job of ignoring pressure in his face. He did it on a pass to Logan Paulsen that was initially ruled a 3-yard catch only to be overturned. Two defenders were about to unload on Cousins when he showed a calm urgency to find him. But the other play I liked was an 11-yard pass to tight end Fred Davis in the red zone. As Cousins dropped back, he quickly looked at his primary receiver. It looked to be mostly a glance to confirm what he thought pre-snap. Cousins quickly left that target and turned to Davis, sticking in a tight throw. One big difference after last year will be the ability to make quick decisions with the ball.

Running back Roy Helu also had a strong night with 57 yards on 13 carries (24 yards came on two runs). He showed why the Redskins like him. He has speed and a lot of it. It seemed early on that he was almost a little too fast to the hole. You have to run with some patience, something starter Alfred Morris does so well. You need to be able to set up blockers, again something that Morris does well. But Helu started to do this as he got more carries. In the second quarter, and facing backups, Helu did a better job being patient, pressing the hole and getting the linebackers to overcommit. So when Helu cut back, he had blockers in position to seal the opening for an 11-yard gain. On an earlier run guard Kory Lichtensteiger lost a block on a cutback run in part because the linebacker was never forced to commit outside. But Helu’s night is a good reminder of why the Redskins need him to stay healthy.

Safety Bacarri Rambo learned a valuable lesson in the opening quarter. The SEC might have speed, but the NFL is at a different level. It wasn’t his fault that Chris Johnson broke through the middle – end Stephen Bowen and nose tackle Chris Neild were blocked inside and linebacker Brian Orakpo went too far upfield, thereby creating a gap. Orakpo seemed unsure if he wanted to go at the ball carrier or play the bootleg. He did neither and the hole was huge. But Rambo failed to do his job as the last line of defense, allowing Johnson to juke him. One of the big transitions for a safety is learning how to tackle in the open field and knowing the proper angle to take. Having said that, it was a tough play to make for many safeties let alone a rookie. He was put in a bad spot, but actually came up fine from deep middle. On another long run by Johnson, it was linebacker Perry Riley who took a bad angle. The young guys in the secondary may or may not be the future. And in the present there will be growing pains. That's why it's not bad that DeAngelo Hall and Josh Wilson sat out the game. It provides more time for rookie DBs in need of a lot of time.

It wasn’t a good night for rookie strong safety Phillip Thomas, who left the game with a shoulder and foot injury. He likely wouldn’t start the season anyway, but he’s someone they like and who has improved at learning his run fits when in the box. Liked what little I truly watched of Chase Minnifield. He is a physical corner, though he did miss a tackle after allowing one catch.

Corner David Amerson had a strong night, showing the advantage of length. He could have played a little more shallow on his intended target, Kenny Britt, on one route in which Amerson should have picked it off. He broke inside and almost baited quarterback Jake Locker to throw the ball, making it appear Britt was open. Amerson dropped the pick, but the point is: His length enabled him to play a little more off his man to the inside. The coaches wanted to see how physical Amerson would play. He is not a big hitter nor is his technique always the best. But at times in college you didn’t always see the willingness. It was much more evident Thursday. Amerson even came up hard on an outside run, ducked under the guard and helped make a tackle for a loss.

Another rookie who stood out: linebacker Brandon Jenkins. The more I see of him, the more I like. The coaches wanted to see how he fared in a game before going overboard about him and certainly they’ll find enough mistakes in his night. But he adds something. And unlike other young players, he had some success against Tennessee’s first-team offense. He helped set up Ryan Kerrigan's first quarter sack. Orakpo collapsed his man on the right side and Jenkins absolutely stunned the right tackle, popping his hands into him before he could react. Kerrigan, in a four-point stance, then worked inside on a quarterback who had nowhere to go. Jenkins later drew a hands-to-the-face penalty on a rush, getting around the tackle. He was noticeable. And I like using him next to Kerrigan. He explodes a little quicker to the outside than Kerrigan, more known for his hands when rushing wide. There was one rush in the second half in which Jenkins stumbled off the line, the right tackle dropped back and Jenkins still managed to get around him. Jenkins needs to learn a lot about the position, notably dropping into coverage. But he showed something Thursday night.

Penalties were a problem last season and they were an issue Thursday (11 penalties). That’s not a stunner considering all the false starts and other transgressions that seemed to take place in camp. The Redskins need to get that taken care of. Early last season they said it stemmed in part from replacement officials. But the issue never really went away. It needs to.

I wish Jarvis Jenkins had made more noise in the pass rush. He’ll be suspended for four games, but still started and played into the fourth quarter. Yet he really didn’t make a whole lot happen in the backfield. He worked on a longer first step in the offseason but it didn’t seem like much was working for him.