Chris Pontius, in red while facing Roger Espinoza and Sporting Kansas City, is entering his fourth season with D.C. United and is returning from a broken leg, but is ready to assume a leadership role. (G. Newman Lowrance/GETTY IMAGES)

Early in 2009, Chris Pontius was a D.C. United rookie midfielder adjusting to the demands of pro soccer and drawing wisdom from, among others, revered midfielder Ben Olsen.

Three years later, Pontius continues to turn to Olsen, but as his coach instead of as a teammate. And all those veterans who nurtured Pontius are gone, leaving him, at age 24, the club’s longest-tenured player.

“It’s weird to think about it that way,” Pontius said Tuesday. “It means I have to step up more and take a leadership role. I am older, I’m more experienced, I’m wiser.”

Pontius’s premature seniority illustrates the extent of United’s roster turnover; defender Dejan Jakovic is the only other 2009 regular still with the club.

While Dwayne De Rosario, Josh Wolff and Robbie Russell, veterans acquired the past two years, are providing leadership, Pontius is embracing broader responsibilities in the effort to end United’s four-year playoff drought.

“It’s definitely a role I want,” he said. “I’ve had the chance to learn over the years, and now it’s my turn to step up on and off the field.”

Pontius is almost certain to be on the field Saturday night when United opens the season against Sporting Kansas City at RFK Stadium.

It would mark his return from a broken leg in September, an injury that ended his finest pro season and effectively ended United’s playoff hopes. Despite De Rosario’s MVP campaign, United wasn’t the same without Pontius making assertive runs on the left flank. With Pontius, United was 8-7-10. Without him, it was 1-6-2.

After rehabilitating through the winter and regaining fitness at training camp, Pontius appeared in the last few preseason matches.

With the season getting underway, Olsen has charted a steady course for him.

“I expect him to have another great year, but I also expect him to simplify the game as much as possible right now,” he said. “He’ll get back to the Pontius of pre-injury soon enough, but right now it’s important for him to play simple — pass and move, do the simple things right because he has been out for a while.”

Pontius started 23 games in his 2009 rookie season, and after his second year was derailed by a hamstring injury, he posted seven goals and five assists in 2011. But in the same match in which he assisted on each of Charlie Davies’s three goals, he broke his right tibia in a collision with a Chivas USA player.

Although he has recovered physically, Pontius now faces the challenge of regaining match fitness and sharpness.

“It’s still coming,” he said. “There are moments where I am rusty with the ball, but it gets better and better every day. I’m getting more confident with the ball. It’s all in due time. I can do everything I want to do and what I used to do. Nothing is holding me back.”

United notes: Less than a week after suffering what was thought to be a broken ankle, Danny Cruz, United’s second-choice right wing, is practicing at full pace and preparing for Saturday’s match. X-rays were performed on both ankles, the result of separate incidents, and no major damage was detected.

“We left [the stadium in Charleston, S.C.] thinking for sure it was broken. All of the doctors there were saying it was broken,” Olsen said. “He’s a pretty durable kid.” . . .

United released Jose Burciaga Jr., a veteran left back who is attempting a comeback after not playing in MLS since 2008.

Rookie central midfielder Lance Rozeboom (New Mexico) is on track to earn a roster spot. Ryan Richter, a second-year pro who has filled several roles in preseason, remains in contention.

Lewis Neal, 30, a left-sided midfielder from England who played for third-division Orlando last year, began a tryout Tuesday.