For three years, Paul Kruger watched Jarret Johnson do the dirty work. Setting the edge. Sacrificing his body. Sometimes chasing down quarterbacks. All the while, Kruger’s position and responsibilities shifted. But now that Johnson has signed in San Diego, vacating his starting outside linebacker spot, Kruger is comfortable, confident and prepared to get filthy in the trenches, too, like his “great mentor and friend” did for nine seasons.

“It’s a great opportunity,” he said Thursday after the team’s voluntary workout in Owings Mills, standing tall with his hands tucked into his pockets. “I couldn’t ask to be in a better situation. So I’m going to be grinding as much as I can from here until August to prepare myself for camp as much as possible. I’m real excited.”

Kruger, 26, shined at times as a situational pass rusher in 2011, recording a career-high 5.5 sacks in the regular season and adding another in the AFC championship game. He mostly played in obvious passing situations, with Johnson manning the strong side on first and second downs. He’s now the front runner in a competition with Albert McClellan for Johnson’s starting spot, but he must first prove he can be that every-down player.

He says he is excited for the challenge, and finally feels comfortable knowing that his future is at linebacker.

The Ravens selected Kruger in the second round of the 2009 NFL draft and he spent his rookie year at outside linebacker. The following offseason, he was asked to pack on pounds for a move inside to defensive end, but he felt sluggish in his new, bulkier body. The Ravens moved him back to linebacker in 2011, and after he flashed the potential that they saw when he was at Utah, they plan to keep him there for the immediate future.

Kruger said knowing where he is playing and what is expected of him “makes all the difference in the world.”

“It’s been tough -- I think a great learning experience -- to kind of bounce around,” Kruger said. “But at the same time, it’s pretty exciting to have a solidified spot that they know they’re putting you into to take it over.”

His main focus during these offseason workouts -- something he and his teammates didn’t have the luxury of last spring -- will be grasping the Ravens defense in its entirety. Watching Johnson while he was here, Kruger learned the importance of being a student of the game and taking the classroom work head-on as if it were a tight end or fullback. And he still gets tips from Johnson. They have chatted a couple of times this offseason.

Johnson leaves big cleats to fill, but cornerback Lardarius Webb believes Kruger is ready to step in.

“A lot of people seen that Paul stepped his game up last year,” said Webb, who was drafted a round after Kruger in 2009. “That’s why they picked him up in that second round -- because Paul is that guy. ... Double-J is going to be a big [guy to replace]. He was a big part of our defense and I think a lot of guys will say that.”

Johnson did the dirty work setting the edge against the run, something that is often overlooked but garners the respect of teammates. As Kruger put it, he “just had that pit bull in him.” So does Kruger have it in him, too?

“You’ve got to be willing to get in there and fight every play,” he said. “That’s why I play the game. I love that stuff. I’m really looking forward to getting out there and playing first, second, third and fourth down, instead of just on third.”