Trea Turner is congratulated by Bryce Harper after hitting his first major league home run. (Mike Zarrilli/Getty Images)

Trea Turner raced out of the batter’s box, flashing his blazing speed. By the time the baby-faced, Dr. Pepper-drinking, candy-eating rookie’s first major league home run clanked off the empty seats in left field at Turner Field, he was already near second base. After easing up and crossing home plate, Turner couldn’t hold back his smile as he walked by Bryce Harper on deck and into the dugout.

There Washington Nationals teammates high-fived the team’s potential shortstop of the future, a skinny prospect known for attributes other than his power. For weeks, in fact, soon-to-be-free agent shortstop Ian Desmond has been teasing Turner about adding more weight to his generously listed 6-foot-1, 175-pound frame.

“For 135 pounds soaking wet, he hit that ball a long way,” Desmond said with a grin.

With six games left, including Tuesday’s 2-1 loss to the Atlanta Braves, and no chance of reaching the playoffs, the Nationals are balancing playing time for some regulars with looming milestones, a few with lingering injuries and young prospects such as the 22-year-old Turner. Tuesday was only Turner’s fourth start since he was called up Aug. 21, and his skills were on full display.

“It’s always nice to hit a home run, no matter if it’s your first or your last,” Turner said. “It’s always fun for me because I don’t hit very many. I enjoyed every second of it.”

Turner went 2 for 3 and held his own at second base, the position he has played the most since reaching the major leagues. His home run was not enough in a well-pitched game between Nationals starter Tanner Roark, who was solid but allowed two home runs to A.J. Pierzynski over 6 2/3 innings, and Braves starter Matt Wisler.

“He might look like he’s 15, but he can play at this level,” Roark said of Turner.

There was little offense. Desmond doubled off the center field wall in the second inning, missing his 20th home run of the season by a few feet. Harper went 0 for 3, dropping his National League-leading batting average to .332, but his walk set a franchise record (Expos and Nationals) at 124, besting Ken Singleton’s 42-year-old mark.

The Nationals had two on with nobody out in the ninth, but Desmond bunted a ball in front of the plate and couldn’t get around Pierzynski, which resulted in an unusual 2-5-4 double play. Regardless, the highlight of the Nationals’ night was Turner, a ray of hope for the future for this disappointing team.

“He’s a good kid,” Desmond said. “He’s got unbelievable ability to hit the ball on the barrel. He’s gonna be a heck of a ballplayer.”

The Nationals cut Turner’s minor league season short by nearly two weeks when they called him up, but it gave him a chance to rest his body after a trying first full season in professional baseball in which he was traded from the San Diego Padres after six months in limbo. And although he wasn’t expected to play much, he has learned a lot from his time in a major league clubhouse.

“It’s been awesome,” Turner said recently. “I’ve always dreamed about it and always wanted to do it and finally got a chance to do it. When I was drafted, I went to San Diego and took some [batting practice]. When I first got here, that’s kind of what it felt like until I got in a game. When I got in a game, I was like, ‘Whoa, this is for real.’ And since then, it’s been fun.”

Turner eased into the setting once he got his major league firsts — hit, start, pinch-running chance — out of the way. He started slowly — 1 for 11 — but has grown more comfortable and hit 6 for 13 since.

“Regardless if you try to or not, you probably press a little bit more than you should,” he said. “You’ve just got to relax and adjust.”

Desmond, the Nationals’ longtime shortstop, has helped Turner, too. Turner has admitted he thought the situation would be “weird,” but Desmond has been “great.” And one of the things Desmond has been teasing Turner about is his scrawny frame.

“He’s been on me a lot telling me I need to gain some weight,” Turner said. “I love Dr. Pepper, and anytime he sees me with a Dr. Pepper he takes it from me.”

The problem is Turner loves, in his words, bad food. He is young, so he burns the calories away quickly. But how will he gain the weight to help his power?

“More food in general,” Turner said with a smile recently. “Less candy and more food.”

Powered by sugar or not, Turner showed some pop in the sixth inning. He smashed a first-pitch fastball from Wisler into those left field seats. After walking through the line of high-fives in the dugout, Turner saw Ryan Zimmerman holding his ball. Turner sat down, and Zimmerman handed him the keepsake.