Washington Redskins linebacker Perry Riley (56) is “light year ahead of where he was” last season, according to defensive captain London Fletcher. (John McDonnell/The Washington Post)

While sitting in film study sessions and playing alongside third-year inside linebacker Perry Riley during these early days of training camp, Washington Redskins veteran London Fletcher has noticed a change.

Drafted in the fourth round out of LSU in 2010, Riley took over as the starter next to Fletcher midway through last season. Riley displayed playmaking ability with 68 tackles and a sack (which would have translated into 136 tackles and two sacks over a full season).

Riley often still had to feel his way along. Not anymore, though. Things are clicking now, Fletcher said. Now, Riley is playing at full speed because he is thinking at full speed.

“Just formation recognition, being able to react quicker as far as knowing, ‘Okay, [this is] what my responsibility is,’ and so when something happens being able to react just half a step faster because he’s more comfortable in what his responsibility is,” said Fletcher, the Redskins’ defensive captain. “He’s light years ahead of where he was just because of that.”

Indeed, Riley has appeared more fluid in practices. He quickly tracks down running backs as they move toward holes in the line, shoots gaps and makes stops. On pass plays, he drops back into coverage with ease and has shown an ability to quickly adapt. He has also managed to keep mental errors to a minimum.

A lot has changed in a year.

Last July, Riley reported for training camp believing he could start as he entered his second NFL season.

Because of the NFL lockout, Riley hadn’t been through a practice in seven months, and he had appeared in only eight games the year before. But he still believed he had a good enough grasp to be able to step into the vacant spot and impress coaches.

“Coming into camp, I felt like I knew it all at the time,” the 6-foot, 238-pound Riley recalls. “But once practice started going, and offenses started doing audibles and stuff, I quickly realized, ‘I don’t have it like I think I do.’”

The Redskins’ decision-makers realized the same thing. They had been hopeful. At that point, they had elected not to re-sign either Rocky McIntosh (the previous year’s starter), or backup H.B. Blades. But with Riley struggling, the decision was made to bring back both McIntosh and Blades. They also added former Pittsburgh Steelers linebacker Keyaron Fox. McIntosh won the starting job and Riley found himself buried on the depth chart.

Eight weeks later, with McIntosh and Fox struggling (Blades was released during the preseason), Riley finally cracked the starting lineup, debuting against the Miami Dolphins.

“I had a lot of things going through my head, and I knew I had to make the most of it and not mess it up,” Riley said.

He didn’t mess it up, recording nine tackles, and he remained in the starting lineup for the remainder of the season. In the offseason the team re-signed Fletcher, and Riley is entering his second season a starter. Together, they will anchor a Redskins defense that is expected to serve as the strength of the team.

“I think Perry is going to be a heck of a football player,” Redskins Coach Mike Shanahan said. “He’s got natural instincts. He’s obviously a lot more comfortable with the system going into this year. … Being around a guy like London Fletcher I think really helps him, and you can see that he’s getting better and better.”

Riley said being able to go through a full offseason of learning from his coaches and from Fletcher did nearly as much to expand his understanding of the defensive schemes.

“From the time we started our offseason program and got working, he has had just this intensity and focus,” linebackers coach Bob Slowick said. “He’s understanding his assignments and how our schemes are supposed to work, and on the field he has that same intensity and he’s just attacking.”

Slowick said Riley and Fletcher are virtually attached at the hip. He sees the young linebacker constantly picking his mentor’s brain. Fletcher said it’s getting to the point where the two see and think alike.

Fletcher sees that chemistry as extremely important, because at times initial plans get foiled, and the two linebackers have to quickly adjust.

“We have to see through the same eyes at that position,” Fletcher said, “because of our responsibilities in the run and the pass. … It starts in the meeting room when we go through film. We see it and talk out that play, and we’re going to play it like this. We’ve done a great job of doing that so far.”

Riley said he has more growing to do and that he hopes with each game comes more familiarity, which will result in a greater impact.

Fletcher and Slowick both say physically Riley lacks nothing, and they fully expect the mental fine-tuning to continue.

Said Fletcher: “Really, I want to get to the point where we have a lot of non-verbal communication between us where we just do things instinctively together. When I was in Buffalo, me and Takeo Spikes would play off each other. Like, ‘Man, it’s drawn up like this in the playbook, but if you see something, then go make a play, and I’ll play off you.’ That’s what I’d like to get to with Perry.”

For now, Riley remains an unknown in the NFL. But he aims to change that with a breakout season.

“I’m not worried about that. If they don’t know, they will,” he grins. “That’s how I think of it, and that’s how I approach the game.”