When Washington Redskins outside linebacker Ryan Kerrigan prepares to face the Cincinnati Bengals at FedEx Field on Sunday, he’ll go through his usual pregame ritual.

It’s nothing fancy, but it does the trick for him. He gets to the stadium and does some running and stretching roughly two hours before kickoff. He’ll return to the locker room, say a few prayers, suit up, and just before re-emerging, the second-year pro scrolls through his iPod and selects Ice Cube’s “It Was a Good Day.”

Kerrigan uses the 1993 hit to help him both focus and relax.

“I try to get myself in the mind frame that it’s going to be a good day,” said Kerrigan, whom the Redskins selected out of Purdue with the 16th overall draft pick in 2011. “I heard the song one day in the offseason and I was going to play some golf, and I heard it and I said, ‘You know what, this is going to be a good day.’ And I played pretty well, for me. I decided, that’s my pregame song this season.”

After selecting that tune, the young pass rusher recorded sacks in two of the three preseason games he played in. He also recorded a sack in each of the first two regular season games.

Kerrigan hopes he can emerge from this Sunday’s game sayingit was a good day. But things just got a lot more complicated for him with fellow outside linebacker Brian Orakpo out for the remainder of the year with a torn pectoral muscle.

The Redskins last season drafted Kerrigan last year to serve as a much-needed Robin to Orakpo’s Batman. Orakpo had been lacking a complementary pass rusher, so offenses could devote the bulk of their attention to the two-time Pro Bowl linebacker and, for the most part, keep their quarterback clean.

But last season, the defense had more balance. Orakpo recorded nine sacks and Kerrigan added 7.5 as the unit improved from 31st in total defense in 2010 to 13th overall in 2011. Redskins officials came away from the 2011 season and looked to 2012 with the belief that they indeed had found their dynamic duo.

But those plans are now on hold.

Kerrigan is now thrust into the leading role, and backups Rob Jackson and Chris Wilson will alternate as his sidekick.

“He’ll probably get more attention from the offensive line as far as sliding to his side, protecting, chipping with a back or tight end,” inside linebacker London Fletcher speculates. “He has to be aware of those things now.”

Kerrigan is aware, but tries not to think about it. He knows his coaches expect him to step up, but as he did last year and prior to Orakpo’s injury this year, Kerrigan is trying to focus on executing rather than worrying about the magnitude of his role.

“You really can’t put too much pressure on yourself because then you really start to stress out. When I saw ’Rak and Carriker first went down, at first I started thinking, ‘Okay, I’ve got to do this.’ I was kind of wearing myself out. But I’ve just got to go out there and do my job.”

Kerrigan chooses to focus on the fact that he was already expected to have a greater impact this season, with or without Orakpo on the field.

His production last season — 68 tackles (fifth on the team), 7.5 sacks (second) and four forced fumbles (first), as well as an interception and touchdown — came despite the fact that the NFL lockout prevented him from being able to spend any time during the offseason studying the Redskins’ defense with his coaches. That certainly would have helped as he learned to play standing up rather than in a three-point stance, and drop back into pass coverage.

He also experienced success despite missing a significant stretch of his rookie training camp after spraining his knee during the very first practice. But a quality work ethic, high intelligence level and impressive strength all enabled him to overcome the early obstacles.

“For a rookie to walk in with no OTAs, no minicamp and walk in, have two weeks practice, start a NFL game and cover the way he did. To do what he did sack-wise and get an interception for a touchdown is pretty impressive,” defensive coordinator Jim Haslett said.

But the coach wants and needs more now.

“I would like to have him step up,” Haslett said. “When you lose one of your edge rushers, the other guy has to step up and get in that double-digit sack range and get a little bit more pressure.”

Kerrigan aims to deliver. With a full season and offseason under his belt, he is at ease in the Redskins’ system and says he now thinks and feels like a linebacker, rather than a defensive end trying to play linebacker.

He still is looking for improved consistency, however. Although Kerrigan had a sack in each of his past two games, he expressed disappointment with his run defense. He’s playing faster, which helps him beat blockers, but he said he has missed opportunities to stop running backs for losses.

“You’ve certainly got to be cognizant because as a pass rusher, any time you have an edge, you want to get upfield, but you can’t get upfield so far that you create a seam in the running game, and I’ve run into that a couple times this season,” Kerrigan said. “It’s just a matter of getting off blocks and finding a balance of being patient and not getting too far upfield.”

Although he can find faults in his game, opponents view him as a player they must account for.

“He’s really done a nice job,” said Bengals Coach Marvin Lewis, who will face Kerrigan Sunday and coached him at the 2011 Senior Bowl. “I think Jim and the defensive coaches there have done a great job of helping him make the transition from being a down guy at Purdue to really a game-changing type outside rusher. . . . I know he’s had to put a lot of work into it. He seems knowledgeable about the game and what they want him to do defensively, and he’s been very effective in his first two years.”

Despite the apparent ease with which he played last season, Kerrigan has longed for the comfort level he had back at Purdue, particularly his last two seasons, where he recorded a combined 136 tackles, 25.5 sacks and 12 forced fumbles.

“It was like, you’re in such a zone that everything slows down,” Kerrigan recalled. “And you know what’s coming and it doesn’t matter what the offensive line does, you know you’re going to get there. It’s the best feeling.”

Kerrigan says the closest thing to those Purdue days that he has felt as a professional was in Week 10 last season, when he recorded six tackles, two sacks and two forced fumbles against the Miami Dolphins. But he believes he is capable of — and needs to be — producing those types of outings on a regular basis.

“I know there’s going to be a lot expected of me now, from my coaches and my teammates, and that’s great. I want to show them I can be that guy,” Kerrigan said. “I just want them to know that I’m an impact player and make big plays, makes the big sack, causes the big fumble and helps us win games.”