For years, Rob Jackson knew his role on defense.

Hand down. Get off the snap. Tackle the ball-carrier.

Real simple.

Jackson played defensive end his entire career, from high school in Connecticut to college at Kansas State to his first two years with the Redskins.

Now Jackson must not only change his position, but also re-train how he plays defense.

In Jim Haslett's defense, Jackson is now an outside linebacker.

Instead of lining up in a stance, he must stand behind the line of scrimmage and read the offensive set.

It's more responsibility, certainly.

"Mentally, it's just a different mindset," Jackson said. "You have to listen for all the calls and you have to be prepared more than you do as a defensive end."

Jackson joined the Redskins in 2008 as a seventh-round draft pick (242nd overall).

He saw limited playing time as a rookie and spent most of last year on the practice squad. He has played in eight games in his brief NFL career, posting two tackles.

Jackson is among several defensive linemen transitioning to linebacker this offseason. Brian Orakpo, Andre Carter, Chris Wilson, Lorenzo Alexander and Jeremy Jarmon are now listed as linebackers in Haslett's system.

Jackson, listed at 6-4 and 269 pounds, says he enjoys the nuances of playing linebacker.

"I'm finally starting to get comfortable standing up [as a linebacker]," he said. "You can see a lot more than you can with your hand down [as a defensive end]. You can see what's coming at you before it happens."

The biggest difference between the two positions?

"Playing coverage," he replied. "I know I can rush the passer, but I've been working on playing coverage and knowing which I receiver is my responsibility."

Jackson knows he must stand out in training camp and preseason to secure a roster spot.

He views playing linebacker as not only a new beginning but also a chance to establish himself in the NFL.

"It's really all about opportunity," he said. "When an opportunity presents itself, you have to take it and run with it."