London Fletcher sat near the sideline last week, a more common sight now, and watched as his teammates practiced.

Fletcher has a lingering ankle injury, or he doesn’t need as much practice as his Washington Redskins teammates, or, at age 37, he has just earned a Wednesday off. Whatever the reason, the team’s best inside linebacker is absent from more practices these days, and it’s fair to wonder if this is what it looks like when a long career hits its twilight.

A week or two earlier, Lorenzo Alexander, another Redskins linebacker, asked Fletcher why he was on the sideline. Fletcher looked over.

“Wait till you’re 37,” he told Alexander.

Throughout the week, Fletcher looks every day of his age. He has flecks of gray in his stubble and occasionally limps through the locker room. But his teammates say something happens on Sundays. For those three hours, Fletcher seems hungrier and more able than his younger teammates. He plays the same way he did more than a dozen years ago, when, as a 5-foot-10 long shot, he began his career with two Super Bowl appearances in four seasons with the St. Louis Rams.

On Sunday, the aging linebacker again played with a rookie’s energy and a starving man’s hunger. He drifted backward and a few steps to his left as Philadelphia Eagles quarterback Nick Foles released the ball.

Fletcher was there for his fifth interception of the season. It seemed like a bad pass by a rookie, but Fletcher’s teammates and coaches believe there’s more to it, that Fletcher has a sixth sense for predicting offenses’ plans.

The play helped preserve the Redskins’ six-game winning streak and added another impressive moment to a career that includes Fletcher’s own streak: 239 consecutive appearances and 198 starts in a row. Since making the Rams’ roster as an undrafted rookie in 1998, he has never missed a game.

“Amazing,” linebacker Perry Riley said of his teammate’s run. “That’s unheard of.”

Things that seem impossible to some are reality when Fletcher is involved. Like a six-game winning streak, a rejuvenated defense and Redskins on the verge of getting the old man back to the playoffs.

Prep work

For nearly six full seasons, the Redskins have been waiting — no, planning — for Fletcher’s career to show its age and the curtain to fall.

It happens to every player, no matter his talent or longevity, sometimes in his early 30s. His legs go, or his instincts dull. The only question is when it will happen, leaving the player’s abilities diminished and the team that’s paying him with a hole in its lineup.

Preemptively, the Redskins have drafted six inside linebackers since 2007, when Fletcher joined the team, and brought in more via free agency. Defensive coordinator Jim Haslett said last week that the team had Fletcher in mind when it drafted Keenan Robinson in the fourth round in April.

“When you have an older guy,” Haslett said, “who maybe someday. . . ”

He didn’t finish the thought. Aging players don’t care for this topic; young players don’t like it much, either. It’s something like discussing a no-hitter. While the spectacle is ongoing, it’s best to just keep quiet and enjoy this slice of history.

Riley likes to ask Fletcher questions, and Fletcher, a gruff and occasionally moody veteran, is usually happy to oblige. In return, they take a businesslike approach to the game, at least when Fletcher is around.

“There’s a time and place to joke,” Fletcher said, “and there’s a time and place to be serious. When I’m playing a sport, I don’t joke too much. I just want to win.”

The younger players marvel at how seriously Fletcher takes his job. When they arrive at the team facility each Saturday for a 20-minute walk-through, the week’s final tuneup, most players wear sweats or whatever they had on when that morning’s alarm sounded.

But Fletcher arrives early, pulls on team-issued gear, cleats and gloves, and takes Saturday’s work as seriously as any other day’s. It’s the way he has always done it. Just because a man built himself into a three-time Pro Bowler doesn’t mean he’s forgotten how it felt to go undrafted out of tiny John Carroll University, a Division III school in Ohio.

“I’m a guy who takes that part very seriously, the prep work,” he said.

This is what brought him to the NFL, and now it’s his mastery of football’s details that is keeping him here. Haslett said he’s coached only two players with a similar understanding of the game: Rod Woodson, the Hall of Fame former defensive back, and Darren Perry, now an assistant coach for the Green Bay Packers.

Haslett walks with Fletcher sometimes, vocalizing the squiggles and lines that pass through his mind. Coaches see plays as diagrams and words like “tornado” and “fire.” Usually players begin studying their coaches’ complex plans on Wednesday evenings, four days before a game. Fletcher sees what Haslett sees; he can visualize not only the plan but how it’ll play out. Haslett said Fletcher can watch film and, 15 minutes later, walk to the field and execute what he saw.

“I love talking to London,” Haslett said, “because it’s like talking with my coaches.”

Teammates love it, too. Riley said Fletcher can see how an offense lines up — a tight end lined up here or there, a wide receiver crowding the line of scrimmage or not — and predict which play is coming.

“As far as his football IQ,” Alexander said, “nobody can even match him.”

Riley believes Fletcher is some kind of football clairvoyant. Haslett isn’t sure the veteran doesn’t have a photographic memory. Is that what led to Fletcher’s interception of Foles on Sunday in Philadelphia, knowing exactly where to be and when to be there?

No, Fletcher said with a chuckle, there’s nothing superhuman about his mind. This is experience at work, and if it seems rare or unusual, it’s because it is. Fletcher and Tampa Bay cornerback Ronde Barber are tied with 239 consecutive appearances; only eight players have gone longer without missing an NFL game.

As the streak continues, time passes and teams — including his own — wait for Fletcher’s skills to deteriorate, he keeps outlasting his replacements. Of the six linebackers drafted since ’07, only Robinson and Riley remain with the Redskins. As for the other four, their curtains have already fallen.

Fletcher’s influence

Josh Wilson’s phone rang during the 2011 offseason. The free agency period was winding down and the former Baltimore Ravens cornerback had several offers. Washington’s was for the least money.

“It’s London Fletcher,” the caller said.

Wilson knew of Fletcher, not as a peer but as an icon. Wilson was 13 years old in Fletcher’s rookie season, 1998. He watched Fletcher start for the Rams as they defeated Wilson’s favorite team, Tennessee, in the Super Bowl. Now, so many years later, Fletcher wanted Wilson to join him in Washington.

Wilson responded, telling Fletcher that the Redskins had offered the smallest contract. Later that day, Wilson said, Washington increased its offer; the young cornerback signed with the Redskins, not just for money but also because of the chance to play with Fletcher.

The only thing more impressive than Fletcher’s longevity is his influence. As the regular season finishes this week, no player better represents the Redskins’ defense: an unlikely contender that might not look the part but has commanded attention and respect.

“Makes me appreciate the hard work he’s put in for this team,” Wilson said, “and see what I have the ability to do.”

Last Thursday, another practice behind him like hundreds before it, Fletcher admitted that recovery takes more time than it once did. The soreness fades more slowly. More time must be spent stretching and getting massages and working on soft tissue.

“Ten years ago,” he said, “you can jump out of the bed and just run full speed.”

Now, the team allows him his days off, when he sits on the sideline and waits for another Sunday.

“I don’t feel that good,” said Fletcher, whose contract runs through the 2013 season. “I probably feel good for about three hours a week. That’s the only time you really have to.”

He said he has no idea if this will be his last ride, or when he’ll even know that answer. The decision to play, he said, hasn’t come in recent years until late in the offseason.

“When it’s time, it’s time,” he said, “and that’ll be that.”

But if this is it? Sure, he said. Reaching another playoffs would be a fine way to end a season, if not a career. If that happens, the same as an undersized linebacker reaching the NFL, who knows how long the ride might last?