Bryce Harper celebrates six-year MLB birthday anniversary of April 28, 2012 debut...

“This guy in Spring Training this year fit in perfectly with the ballclub in the clubhouse, and there was a maturity about him and professionalism about him that we hadn’t seen the year before,” Mike Rizzo told MLB Network Radio’s Jim Bowden and Jeff Joyce after the Nationals decided to bring 2010 No. 1 overall pick Bryce Harper up to make his major league debut on April 28, 2012, six years ago today.

“This guy’s taken a lot of strides and a lot of steps in his career,” Rizzo continued, “in a short professional career, and I think he’s a guy that, he’s a special guy and he’s got some special skills and the player development guys, every coach and every coordinator, manager, from Bob Boone to Doug Harris, they’ve done a terrific job with this guy, expediting his developmental curve to the point that it gave me the confidence to know that he could handle anything that they throw at him on the big league level.”

Harper was ready. He put up a .270/.340/.477 line with 26 doubles, nine triples, 22 homers, and 18 steals in 139 games and 597 plate appearances, over which he was worth 4.4 fWAR, earning a Rookie of the Year award for his efforts in his rookie campaign in 2012.

Six years later, the now-25-year-old right fielder, who won the National League MVP award in his fourth season, and is potentially headed for free agency this winter, celebrated the sixth anniversary of his MLB debut with a throwback pic on Twitter:

His fourth manager in his seven major league seasons, Davey Martinez, talked before the start of this afternoon’s matchup with the Arizona Diamondbacks about getting to watch Harper play on an everyday basis before the 795th game of the outfielder’s career.

“Happy Major League Birthday to Bryce Harper. 25 years old, six years, pretty impressive,” Martinez said.

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“What’s funny is you look at him, and he still looks like — to me he looks like a baby. I’ve got kids older than him. But knowing that he’s been around for such a long time, you look at him as a young veteran, really. And his presence in our clubhouse and on the field speaks for itself. So, I’m really happy for him and I’m glad I get to manage him every day.”

Martinez also recounted his first interaction with the outfielder from his time as a bench coach with the Tampa Bay Rays.

“The first time that I met him was — we came in with Tampa and he walked by and I grabbed him,” Martinez recalled.

“I said, ‘Hey, I just want you to know I love the way you play the game.’ I said, ‘Keep playing the game hard like that, don’t let anybody tell you not to, just be you.’

“He said, ‘Hey, thank you. I appreciate it.’ And he’s been the same, he hasn’t changed a bit.”