The most noticeable offseason upgrades for the Washington Redskins came on the defensive side of the ball, and for much of Friday night at FedEx Field, it's safe to say the Pittsburgh Steelers noticed.

The Redskins played most of their defensive starters for the entire first half of Friday’s 16-7 win over the Steelers. Coming off a season when the Washington defense allowed more yards per game (389) than all but one other NFL team, the Redskins starters gave up just one touchdown and 129 yards of offense in the opening half.

In 16 regular season games last season, the fewest yards the Redskins allowed to any team was 309. In their preseason opener, a revamped defensive unit held the Steelers to only 186.

“I think we still have a lot to work on,” said newly-acquired defensive end Stephen Bowen. “We’re working towards a goal to try to get better. Hopefully by the season, we’ll be right where we want to be.”

Perhaps more important than anything in the box score: the Steelers were 0 for 4 on third-down conversions against Washington’s first-teamers, as Redskins defenders came up with big plays when they were needed most.

Pittsburgh quarterback Ben Roethlisberger stayed in the game for just one possession, moving the ball near midfield. Facing third and seven on the Steelers’ 46-yard line, Washington defensive coordinator Jim Haslett called for a nickel package. Linebacker London Fletcher blitzed up the middle, followed shortly by cornerback Kevin Barnes, who was able to wrap up Roethlisberger for a nine-yard loss, ending the drive.

The addition of nose tackle Barry Cofield and defensive end Stephen Bowen, both of whom arrived via free agency, created lanes in the middle for pass rushers that didn’t exist last season.

“There’s obviously some work to do,” Cofield said, “but for the first time out with all the circumstances that surrounded this, I think we did pretty well.”

On their next drive, the Steelers again crept toward midfield and again stalled on third down. This time, it was Bowen, the former Dallas Cowboy, who made his presence felt. Haslett again called for a blitz, but Bowen found an open path to quarterback Byron Leftwich and rocked him for a 10-yard loss.

Upgrading the defense and finding players suited for Haslett’s 3-4 scheme was a priority this offseason in both free agency and the draft. Redskins’ rookies had their moments as well.

On Pittsburgh’s first possession of the second quarter, the Steelers faced third and one from their own 29-yard line. First-round draft pick Ryan Kerrigan, who was playing his first game at outside linebacker after spending four years at Purdue as a defensive end, breezed through the line and stopped running back Mewelde Moore for a 1-yard loss.

Kerrigan missed a week of practice with a knee injury and his unfamiliarity with the new position was evident at times. “It's like all, I think, rookies — there's some good, some bad,” Shanahan said. “It's a learning experience. By no means is it perfect, but I was pleased with the effort. I think he's going to keep on getting better.”

The Redskins also relied heavily on Jarvis Jenkins, the second-round pick out of Clemson. Jenkins replaced Adam Carriker at defensive end and played the rest of the half with Washington's first-team defense at both right and left end.

“The first preseason game, it’s going to be a little bit of rust,” Jenkins said, “gonna be some errors, but the main thing was we didn’t have any mental busts.”

The unit’s biggest struggles came in the secondary. The Redskins were without both of their top safeties — LaRon Landry and Oshiomogho Atogwe — and their starting cornerbacks were both beat on deep routes--DeAngelo Hall twice and Josh Wilson once. The Steelers overthrew their receivers each time, however.

Pittsburgh’s touchdown came in the second quarter, when Isaac Redman spun through the left side and found some room, running past outstretched Redskins’ hands for a 22-yard score.