Jaromir Jagr has four points in five games with the Flyers after spending the past three seasons in the Kontinental Hockey League. (Bruce Bennett/Getty Images)

When the Washington Capitals take the ice Thursday night in Philadelphia, there will only be one player on their roster who remembers what it was like 10 years ago, when the team had completed a blockbuster trade for Jaromir Jagr.

There is only one player who remembers how the experiment failed and management jettisoned Jagr after 21 / 2 seasons during which the former NHL scoring leader never lived up to the hype with which he arrived. How correcting the error marked the beginning of the Capitals’ decision to tear up their roster in 2004 and rebuild.

“The nucleus of these guys, they don’t know the Jagr era here,” Jeff Halpern said earlier this week. “The book has pretty much been sealed off and those pages have been turned, but Jags really was the first domino to fall when things really started changing and they began building what is here now.”

When the 2011-12 Capitals, led by their cadre of offensive thoroughbreds, take on a revamped Flyers squad they will face Jagr, 39 and back for an encore in the NHL after spending the past three seasons in Eastern Europe’s Kontinental Hockey League. Washington will be the first of his three former clubs, along with Pittsburgh and the New York Rangers, that Jagr faces this season after signing a one-year deal with Philadelphia worth $3.3 million.

“The part of me playing there I’d like to forget. I wasn’t very good,” Jagr told reporters in Philadelphia on Wednesday, when asked about his time in Washington.

In five games with the Flyers, Jagr has recorded four points (all assists), but he also has shown himself to be an effective leader and eager to help teach his younger teammates. It’s not the reputation he developed as a moody hot shot, unable to mesh with teammates in Washington, earlier in his career.

Those who have had contact with Jagr in recent years, such as Capitals goaltender Tomas Vokoun, say they’ve noticed a new maturity in the winger and aren’t surprised by the positive reviews of his presence in Philadelphia.

“I think he changed from obviously being a top scorer to being a really good team guy,” said Vokoun, who won a gold medal with Jagr on the Czech national team at the 2010 world championships. “He was a leader on that team. Not necessarily you can expect him to score two goals every game, but hats off to him. People weren’t so sure about him as a team guy and a team player in the past, but he [has changed] a lot the last few years — at least from my own perspective.”

Capitals General Manager George McPhee and owner Ted Leonsis declined to comment for this story. Leonsis said through a spokesman that he prefers to “not comment on a former player who currently is playing for another NHL team.” But both have publicly acknowledged in the time since Jagr was traded to the Rangers in January 2004 that his addition to the Capitals was, as McPhee termed it, a “bad chemistry experiment.”

After acquiring Jagr from the Penguins in 2001, the Capitals structured their roster and style of play around him. Washington signed Jagr to a seven-year, $77 million contract extension, but he never recaptured the success of his early career with the Penguins. The Capitals missed the playoffs by two points in his first season with the team and then lost in the first round of the playoffs in the second year.

“Maybe I didn’t play the way I should play,” Jagr said. “The owner got me to win the Cup, at least to get a little further in the playoffs, and it didn’t happen.”

Even after sending Jagr to New York, where he rediscovered his scoring touch, recording 123, 96 and 71 points in three full seasons with the Rangers, Washington wasn’t financially free of Jagr’s presence.

In order to trade Jagr, the Capitals agreed to pay a large portion of his contract, even though he didn’t play for them, through the 2007-08 season. After that year Washington also paid, as did the Rangers, a smaller cash fee owed to Jagr because an option year on his contract did not kick in after he missed performance benchmarks.

While postseason disappointment is a refrain that continues for the Capitals, there is a distinctly different air about Washington now than in the days when Jagr was on the roster, according to Halpern. The 35-year-old center said he senses a different feeling about the Capitals’ pursuit of success in his second stint with his hometown team, explaining that there’s an allegiance in the locker room to Alex Ovechkin as a franchise cornerstone that was never present with Jagr.

“Guys want to play hard for Ovi,” Halpern said. “They see his drive, his passion for the game, and when Ovi plays as hard as he does and has that kind of passion the team follows. For whatever reason the team never really had that identity with Jags.”

Capitals notes: Jay Beagle missed a fifth consecutive practice and has not skated since he was knocked out by Pittsburgh’s Arron Asham on Oct. 13.

Michal Neuvirth skated for 30 minutes but did not take part in regular practice Wednesday. The goaltender has missed three games with a bruised right foot.