His talent is unquestionable, but it's the rookie's desire and maturity that impress the Nationals most

Bryce Harper tagged the base and then turned to face his onrushing teammates, a huge grin spread across his face. He had just swatted a single into left field to lift the Nationals to an extra-inning win against the New York Mets on Monday, and his teammates were after him.

The crowd roared, Ryan Zimmerman jumped into Harper and tried to pull his jersey over his head and Michael Morse doused him with cups of Gatorade. It certainly won't be the last time Harper, a 19-year-old rookie outfielder, plays the hero at Nationals Park. He has been in the big leagues now for 43 days. That is a tiny slice of what should be a long, distinguished career, and this was his first walk-off hit. But even as he beamed afterward, Harper took his accomplishment -- the first teenager with a game-ending hit since 1988 -- in stride.

"I'm pretty [angry] I went 2-for-7. I shouldn't have done that," Harper told reporters, only half-joking. "I'm happy to get the [win] tonight, of course. I'm happy to get that walk-off hit. But I don't like going 2-for-7. I don't like striking out twice in one game, either."

Baseball's best ever at 19 years old
Bryce Harper, Washington Nationals » The rookie outfielder entered Friday with a .276 batting average, five homers, four triples, seven doubles and an .859 OPS. Harper has struck out a reasonable 25 times and walked 17. There are other rookies with better stats in 100 or more at-bats this season, including fellow phenom Mike Trout, a 20-year-old outfielder with the Angels. But only Trout, 14 months older than Harper, is even close to the same age. Everyone else, including Boston third baseman Will Middlebrooks and Cincinnati third baseman Todd Frazier, is between 23 and 26.
Mel Ott, New York Giants » The gold standard for rookie phenoms, Ott made his big league debut at 17. In a full season of 500 at-bats at age 19 in 1928, Ott hit 18 home runs, batted .322 and had a .921 OPS.
Mickey Mantle, New York Yankees » The player Harper is compared to most wasn't quite ready for the majors. He made the team out of spring training in 1951 but quickly returned to the minors. He eventually returned to hit 13 home runs in 341 at-bats with a .792 OPS and a .267 average.
Ken Griffey Jr., Seattle Mariners » He registered a .748 OPS at age 19 in 1989. In 455 at-bats, Griffey hit 16 home runs and had 16 stolen bases all while playing center field.

It was a little window into Harper's competitive nature. His physical tools are what inspire awe even among jaded professionals: the bat speed, the hand-eye coordination, the power, the throwing arm. All of those give him a shot at becoming an All-Star, maybe even an MVP someday.

"One of the best players I've ever seen, to be honest," teammate Ian Desmond said of Harper, who won't turn 20 until Oct. 6.

But his desire to build on those tools might push him to become the greatest player of his generation.

"He's a man child. This guy's unbelievable," Morse said. "He's really learning this game. Every day I think he's taking something in with him. And when he comes out here and he plays like he plays, it's fun to watch. It's good to have him on our side."

Even Washington general manager Mike Rizzo, a former scout who holds dear his player development tenets, has admitted that players like Harper just can't be held back. The Nats were thin in the outfield to start the season with Morse hurt and center field a question mark. Then Zimmerman went on the disabled list April 27 with a sore shoulder, and the lineup was in shambles. Harper was summoned to Washington from Triple-A Syracuse ahead of schedule and amid worries that he wasn't ready quite yet. But he won't be going back, and that's not a surprise to some.

"I think the whole rookie thing is the biggest overrated thing in sports. Baseball here is the same as baseball in Double-A," Zimmerman said. "Just like kids in college play basketball and then they go right to the NBA -- it's the same game. It's just that he's learning at this level. If you're talented enough to play at this level, you might as well learn here."

Nats manager Davey Johnson has been making that argument since September. He saw the electric impact of elite, young talent firsthand when phenoms Dwight Gooden and Darryl Strawberry helped his Mets win the 1986 World Series.

But it is Harper's demeanor that has shocked them all more than anything. The knock on him as an amateur -- and even as recently as last summer in the minors -- was that Harper was too brash, too bold for his own good. It was one of the reasons hinted at by Philadelphia pitcher Cole Hamels when he admitted to drilling Harper on purpose during a May 6 game in Washington.

Multiple teammates say they haven't seen that side of Harper in the clubhouse. What they have seen instead is a baseball rat with Hall of Fame talent, a supreme confidence in his own ability mixed with a willingness to ask questions and admit he doesn't know everything. That has brought acceptance and also exposed Harper's biggest accomplishment yet -- making his own teammates forget how young he really is.

"Anything he's done surprised me? Yeah. Every single thing that he does," relief pitcher Ross Detwiler said. "I don't think of him as a 19-year-old kid, but that's exactly what he is."