Nationals second baseman Anthony Rendon will try to fill the gap left by departed teammate Ian Desmond. (Katherine Frey/The Washington Post)

Behind the pearly white smile, quick swing and flashy defense at third base, Anthony Rendon is reserved. His interests include hanging out with family, golfing, watching the Houston Rockets and sleeping. He shuns attention and is often terse in interviews. But Rendon will try to come out of his shell this season for a worthy cause.

At the urging of former Nationals shortstop Ian Desmond, Rendon will join the board of the Nationals Youth Baseball Academy and become the lead player spokesman for the team’s charitable arm. And in doing so, the 25-year-old will find himself in the spotlight more than ever because helping inner-city kids means so much to him.

“I’m slowly trying to get out of my comfort zone,” Rendon said, sitting in the dugout at Space Coast Stadium after a morning workout. “That’s the hardest part, getting out of my comfort zone and doing more in the public, for the kids or for the team. That’s not the type of person I am. I’m trying to mature and work on that. And understand that, if I want to do something and put my mind to it, there’s going to be other variables that come with it. I’ve got to learn how to handle it and do it.”

When the Nationals drafted Rendon with the sixth overall pick in 2011 out of Rice University, they knew his standout talent could land him in the majors quickly. He played 57 minor league games before his big league debut April 21, 2013. He had to grow up quickly.

“I know a lot of times fans get frustrated with the fact that he’s often smiley or doesn’t give serious answers in the media and jokes around a little bit,” said Desmond, now with the Texas Rangers. “But he’s very passionate about his job, even though he doesn’t let it on all the time. He’s trying to leave a bigger mark than just batting average and Gold Gloves and all that.”

In Desmond, Rendon had a role model he admired for how he carried himself on and off the field. Rendon noticed Desmond sneaking out of the clubhouse after pregame batting practice to speak to academy kids visiting Nationals Park.

Desmond, a board member since the academy opened in 2014, began inviting Rendon to come, too. He knew his time as a National was likely coming to an end and remembered that Rendon did offseason charity work in his home town of Houston.

“I always saw the way he interacted with the kids that would run onto the field or just around,” Desmond said. “Without having kids, he’s very comfortable around kids. He knows how to speak to them and understands how to get on their level. I know he’s got a big heart for that, and I know where his heart is at. That’s what that academy needs.”

So in a late-season meeting, the two met with academy Executive Director Tal Alter so that Desmond could begin laying the groundwork to pass the torch to Rendon. Desmond’s faith in him motivated Rendon to take on the responsibilities.

“Seeing how the kids react to you is pretty awesome,” Rendon said. “Not necessarily that they’re star struck, but they’re shy. They’re kids. They don’t know how to act to a new person. I know that feeling because I was there not too long ago. Sometimes I still feel like that with the guys you play with and growing up watched and now play with.”

Rendon met with Alter recently in Viera to finalize plans for this season. Desmond will remain a board member emeritus; Rendon will replace him as the academy’s go-to player representative. He will be involved with the board’s decisions and direction. He will host groups of players and their families at least monthly at Nationals Park. He also hopes to make regular visits to the academy to work individually with kids who need special attention.

“Anthony is entering a similar phase in his career as the academy,” Alter said. “For him to be maturing as a player at the same time the academy is maturing, it’s a cool sort of synergy. We’ll always miss Ian, but I think Anthony is more than ready to take on the role. It’s going to be his program now.”

Rendon said he is impressed with the academy’s 18,000-square-foot, two-floor facility in Southeast Washington that includes a garden, kitchen, seven classrooms and three artificial turf fields. Built primarily with city money, the academy hosts 144 third- to seventh-graders from Wards 7 and 8 for academic and baseball programs after school three times a week during the school year and in the summer. The fields also host hundreds of events a year, and the academy hopes to launch recreational baseball and softball leagues so kids 6 through 12 have affordable chances to play. Among the things Rendon said he cares about teaching kids is healthy eating as the country’s obesity rates rise.

“Say throughout the lunchroom, ‘Oh, I want that Snickers bar,’ but there’s a banana or apple right here,” Rendon said. “Make them choose the apple, and if something from the academy triggers their brain, that’s good. If we can change one or two kids’ lives out of the whole program, that’s positive for me.”

Rendon values his privacy and doesn’t want to be seen as doing charity work for the recognition. But because he is under team control for another four seasons, he wants to develop stronger ties to the community and become a role model. Alter said Rendon’s transformation can be a lesson for the academy students.

“There’s more in this world than just baseball,” Rendon said. “Everybody puts us players on a pedestal. ‘Oh, they’re baseball players and they’re making this much money so they have to do this perfect and that perfect and can’t mess up.’ But we’re human beings as well. We have our great days and our bad days. No matter what bad day I go through or strike out four times in a row, I still want to have that great attitude and go after the game and go talk to the kids and not worry about the game and let them know that this is what matters.”

In a way, Rendon sees his own experiences in the academy kids. “I wouldn’t say I grew up in the worst neighborhood in the world, but it wasn’t the best either,” he said. Rendon credits his parents and travel baseball coach Willie Ansley for guiding him as a youngster in Houston.

“A lot of my friends went down that path, and I still talk to them to this day,” he said. “With some of them, to see how their lives could have changed if they had the right sense of direction or someone in their life. . . . If we can get to the kids and teach them great values and help them mature and how to be young, strong adult men and women, then you’re slowing that process.”