Troy Brouwer, center, won a Stanley Cup with Chicago, but, from left to right around Brouwer, Mike Green, Nicklas Backstrom, Alex Ovechkin and Alexander Semin have yet to advance past the second round of the playoffs. (Toni L. Sandys/THE WASHINGTON POST)

In the middle of the 2007-08 season, the Washington Capitals designed a promotional poster to appear yellowed and aged featuring the Wild West-style type. Pictured were four shaggy-haired players: Mike Green, Alex Ovechkin, Nicklas Backstrom and Alexander Semin. The label below them? “Young Guns.”

As the Capitals prepare to begin their 2011-12 campaign against Carolina on Saturday night at Verizon Center, the moniker still exists, but the guns aren’t so young anymore. Four years — and four straight postseason disappointments — later, each must bounce back from an individually lackluster season while shouldering the greater burden of leading Washington’s pursuit of the franchise’s first Stanley Cup.

“It’s time that we stepped up, grew up and became, or at least try harder to become, the leaders of this team in everything we do,” Green said. “The time is now. It has to be. At the end of the day, we play the game to win a Stanley Cup, not for anything else. We’ve wasted enough time.”

Last season, Ovechkin and Backstrom each suffered career lows in multiple statistical categories. All four players saw their offensive totals dip anywhere from 24 to 52 points from the previous year. Against the Tampa Bay Lightning in the playoffs, the Capitals were swept without much resistance from the big four who combined for three goals and five assists in the series. In Game 4, the only one to record a point was Ovechkin, who tallied an assist.

“We’re experienced guys now, not young guys, and you learn what missing an opportunity costs you,” Ovechkin said. “It can be our last chance, us guys. You never know what’s going to happen, how many chances, opportunities you’re going to get. How many players was a great player but never won a Stanley Cup? A lot. I don’t want to be that. None of us do. We must do better.”

There is a feeling among those close to the organization that if the Capitals depart the postseason early once again, there will be significant changes. Green and Semin are set to become free agents next summer, the same time the NHL’s collective bargaining agreement expires and likely alters which players teams can afford to keep.

“Things can go fast in this league,” General Manager George McPhee said. “If you look at Semin, Green, Backstrom, Ovi, they’re five, six, seven years into their career. Their careers could be half over, and I think they’ve started to realize this isn’t going to last forever. They don’t want to leave anything on the table, because the opportunity is there.”

After the Capitals were swept out of the second round by Tampa Bay last spring, McPhee could have made sweeping changes to the Washington roster. Rather than dismantle the core of Ovechkin, Backstrom, Semin and Green, though, McPhee altered the supporting cast.

Out went players with several years in the organization and in came a Stanley Cup winner (Troy Brouwer), an undisputed top goaltender (Tomas Vokoun), a wily veteran defenseman (Roman Hamrlik), a rugged grinder (Joel Ward) and a former captain (Jeff Halpern) to create what might be, at least on paper, the best roster to surround the team’s four pillars.

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When Ovechkin arrived in Washington before training camp last month, everyone in the organization, from owner Ted Leonsis to strength and conditioning coach Mark Nemish, said the 26-year-old was in the best shape of his career. By all appearances during the preseason, the two-time MVP has lived up to the hype after beginning his offseason training regimen early.

Ovechkin made the mistake of believing he could gradually play himself into shape during the 2010-11 campaign, a year in which he recorded career lows in goals (32) and points (85) and was hampered by what is believed to have been a knee injury.

“I need to be ready mentally, physically right away,” Ovechkin said. “From the first game to the last game. Last year it wasn’t this way. . . . Now I know I need to be ready for the year. These months are to build our team for playoffs, we must all be ready at the start.”

A return to past form and scoring prowess by Ovechkin would go a long way to help spark the Capitals’ offense, but his ability to mature as a captain is equally important to Washington’s success.

“One thing we talked to Alex about was in terms of leadership and how he can be a great captain,” McPhee said of the offseason discussions with his star left wing. Both declined to share specifics, but it’s likely Ovechkin was encouraged to speak up a little more when necessary in the dressing room.

“It’s my seventh [season], it’s time to understand what kind position we’re in where there are no more excuses,” Ovechkin said. “If there’s something to say, I will.”

For real change to take place, adoption of the new mind-set needs to be evidenced in the actions of everyone, especially the Young Guns. That includes attending practice to being willing to play in a less familiar position if it would benefit the team. And there is no player whose dedication and actions have been questioned publicly more than Semin.

The 27-year-old Russian sniper came under more scrutiny this offseason when he was the subject of criticism raised by former teammates Matt Bradley, who stated in August that the winger “just doesn’t care,” and David Steckel, who gave his approval to the assessment.

Washington’s management rallied to defend Semin, and Coach Bruce Boudreau stood up for him, stating that the team’s longest-tenured player has been “committed to doing what’s right” since arriving at training camp. Semin also granted multiple interviews in English during the preseason, something that had been unheard of since his NHL debut in 2003.

“This is important year for Caps and for me, too,” Semin said last week. “I want to try to speak English.”

Many of the troubles Green, 25, and Backstrom, 23, faced last season were because of injuries. Backstrom was limited much more than he let on by nagging problems with his fractured thumb and its tendons. This year, he knows he has a chance to re-establish himself as one of the game’s dominant offensive centers and bounce back from a 36-point dip in production.

Meanwhile, Green, who will be a restricted free agent at season’s end, can make the next move in his career, whether as a natural, free-flowing scoring threat, as the two-way player he evolved into in 2010-11 before injuries took their toll, or a hybrid of the two. The biggest difference now, the two-time Norris Trophy finalist said, is that the team’s core players have learned how to carry the weight of expectations.

“I think that in the past we’ve always had that responsibility because people looked up to us on the ice and expected big things,” Green said. “We’re better prepared now. It’s just a matter of us being more mature, making hockey and winning a Stanley Cup our main focus.”

In early July, McPhee flew into the Calgary, Alberta, airport to meet with Green and Backstrom, who was visiting in order to attend the defenseman’s charity golf tournament. The trio had lunch in the terminal and McPhee departed immediately afterward, without ever leaving the airport.

Neither player shared details of their meeting with McPhee, except to say it was about the direction of the team and the expectations for this year. Green added that the conversation was “personal” in nature.

“It was a big thing,” Backstrom said. “We were still upset about last season, and it was good to have the meeting.”

Over the past four years, the Young Guns have each gone through their own phases of accomplishment and struggle, and they’ve experienced the same bewildered disappointment following each postseason exit. To take advantage of the shot they have before it’s no longer available, they have to be the ones to force a change.

“They have to lead the team,” McPhee said. “They’re exceptional talents and they have to play better than they did last year. All of them underperformed, to some degree. They weren’t at the levels they’ve been at before and we need them to get back to those levels. It looks like they’re prepared to have good years, because they’re physically and mentally in the right place now.”