Rookie Bradley Beal was selected by the Washington Wizards with the No. 3 overall pick in June’s NBA draft. (Tracy A. Woodward/The Washington Post)

By the time he was a sophomore at Chaminade College Prep in St. Louis, Bradley Beal had already established himself as the best player and leader on his team, but he still had plenty of room to grow. During one game, Beal made a hand gesture to blow off his coaches and ran the play he wanted instead.

Afterward, Chaminade Coach Kelvin Lee lit into Beal with an angry tirade to remind him that sort of behavior wouldn’t be tolerated on his team. Lee assumed that Beal would arrive at practice the next day pouting, upset and possibly holding a grudge for being shown up in front of his teammates.

“He came in the next day, gave me a fist pump, smiled and he was ready to go to work,” Lee said with a laugh, in a telephone interview. “From that moment on, I never had a problem with Bradley. He’s very grounded. He’s mature beyond his age.”

That maturity contributed to Beal leaving high school as the Gatorade national player of the year, leading Florida to the Elite Eight as a freshman, enter the NBA draft after one year and become the third overall selection for the Washington Wizards.

With the Wizards opening training camp on Tuesday with two of their cornerstone pieces — John Wall and Nene — sidelined with injuries, Coach Randy Wittman hasn’t tried to place any extra or unnecessary pressure on his only rookie. But Beal has already assumed that he will have to accept more responsibility and again play older than someone who turned 19 on draft night last June.

“I’ve been faced with this situation almost all my life. I’ve always had to grow up faster than what I am,” Beal said. “I’m mentally prepared for that, honestly. I’ve always been like that. I’m humble, and guys always say I act older than what I am so I always keep that mentality and make sure everything is focused and serious. It’s a business. So if I have to grow up fast, like everybody wants me to, I’m willing to do that.”

Beal was understandably disappointed when he discovered that he would have to wait awhile longer before he is allowed to share the backcourt with Wall, who will miss the next eight weeks with a stress injury in his left knee.

“We just have to move on, honestly,” he said. “Hopefully, he gets well soon, before the eight weeks are up. But I mean, I have this year, hopefully next year and years down the line [to play with Wall]. When that time comes, I’m definitely going to cherish it.”

Until then, Beal is anxious to assist in filling the scoring and leadership void in the absence of both Wall and Nene. “I may be young, but I can always lead by example and still be vocal in practice and things like that,” Beal said, adding that he expects the team to remain competitive this season despite the early setbacks. “I think this team can be great, honestly, with the assets that we have. Mr. [Ted] Leonsis said it himself; he said there is no reason we shouldn’t make it to the playoffs and not be in the lottery and I totally agree. We have older vets and we have a lot of youth, guys that are willing to win and sacrifice for the team. We have a great chance of making a run for the playoffs.”

The Wizards brought Beal to Washington because of his ability to shoot from long distance and score, but he also showed in the summer league that he is capable of creating scoring opportunities for others. Wittman won’t ask Beal to worry about anything more than his duties as a shooting guard and will likely go with Jordan Crawford as the starter when the season begins.

“Nobody needs to be anything more than they are. This team wasn’t built solely based on one player to carry us,” Wittman said. “We just got to worry about Bradley being Bradley; being a rookie coming into this situation, seeing how much he can handle before we get into deciding to thrust somebody further along than we need to be.”

Beal said he is willing to compete for playing time and would accept any role Wittman gives him. “Just because I’m the No. 3 pick doesn’t make me any different than any other member of the team. That’s how I view myself. But added pressures, I don’t have any,” Beal said. “It’s more motivation, honestly. I just try to motivate myself to be able to always want to get better and always want to be who I am, like Coach Witt wants me to be. I’m just trying to stay within myself and the team concept.”

Lee was certain that Beal wouldn’t have any problems adjusting to his latest challenge — “Bradley has been on the stage all the time. He welcomes that big stage,” he said — and credited Beal’s family and faith for keeping him level-headed. In high school, Beal would read the Bible before games and scribble verses on his sneakers for motivation. Beal said he chose to wear the No. 3 in the NBA party because it’s “somewhat biblical.”

Other than Nene refusing to call him by name and veteran Martell Webster asking him to carry his iPad, Beal has yet to deal with any sort of rookie hazing. And Wall said he didn’t have to pass along much advice to Beal because already “he’s so mature.”

“I’m impressed with his poise,” veteran point guard Jannero Pargo said after watching Beal in practice for the first time. “I think a lot of rookies come in and they press and try too hard. It seemed like he took his time and went hard when it was time to go hard and he looked pretty good.”

Beal did have one slip-up, though. When the Wizards ran some non-contact drills, he slipped while running a curl and fell to the ground. He quickly got back up and laughed about it later.

“I tripped over the line,” Beal explained with smile and moved right along, ready to get back to work.