Does Harper’s hustle hurt his future?

I’d take Bryce Harper over Mike Trout and Manny Machado in the Great Sophomore Debate. I love Harper’s brashness as much as his bat speed. I admire the complete dedication of his body to the cause of winning for three hours each night.

And as a baseball fan, that’s why I’m worried about him.

I watched the Washington Nationals in person Wednesday for the first time this year, but I did not see one of the most exciting players in the sport. Harper will miss the entire four-game series against the Beltway rival Baltimore Orioles because of bursitis in his left knee. Manager Davey Johnson hopes Harper will return this weekend, but he isn’t certain that will happen.

Already, Harper has been out of the starting lineup for almost 19 percent of the Nationals’ games this season — and rising. They are 2-8 without him, including a 9-6 defeat Wednesday in which they blew a four-run lead. Washington is a middling 27-26 and only one game clear of the third-place Philadelphia Phillies in the National League East.

But this is not about the Nationals’ record in 2013. This is about the larger implications of the maladies Harper’s 20-year-old body has sustained over the past month: side muscle discomfort after a checked swing (May 1); removal of an ingrown toenail (May 10-11); left shoulder and left knee injuries, and a bloody chin, from his face-plant into the Dodger Stadium wall (May 13-15); recurrent swelling in the left knee (May 18-19); and now the bursitis (May 27-present).

And it’s not as if Harper has been his normal, productive self during the games in between. Over 38 plate appearances since colliding with the fence at Chavez Ravine, Harper is batting .226 with an ordinary .785 OPS.

The sample size is small. The concern is justified. Harper’s all-out, throwback style of play has inspired comparisons to Hall of Famers and hosannas from around the baseball world (including under this byline). And yet I’m haunted by the fact that we said the same things about Grady Sizemore, who played his last healthy season at age 25 and hasn’t appeared in the majors since 2011.

Johnson said Wednesday he doesn’t want Harper to change his style of play, other than to develop a better awareness of where the fences are. Nationals general manager Mike Rizzo feels much the same way. “I never want to curtail his enthusiasm and the way he plays — that’s who he is,” Rizzo said.

Ironic, isn’t it? One year after the team shut down ace Stephen Strasburg because of an innings limit, the Nationals believe they can do only so much to protect the outfield equivalent.

“Nobody wants me to stop playing hard,” Harper told me Wednesday afternoon. “Maybe being a little smarter out there in a six-run ballgame is the only thing I can think of. But playing hard — that’s how I’m going to play. I don’t think it’s going to shorten my career. It’s just something I’ve always done. So we’ll see what happens.

“I just think about playing hard every day. It doesn’t matter if it’s a 10- to 15-year career, or a 15- to 20-year career, I’m going to play every day like it’s my last. Everybody in this game deserves that. And I (owe) that to myself.”

If that sounds like something an idealistic 20-year-old would say, please allow me to remind you that Bryce Harper is … 20 years old.

But for a player who represents baseball’s best hope of having a LeBron James-level superstar, might it be wise to ease up — just a little — for the long-term good of the game?

“You just have to learn,” said third baseman Ryan Zimmerman, one of the few Nationals veterans with the stature to make such a suggestion. “Obviously it’s better to have someone have to tone it down than not play hard enough, and have to continuously yell at someone.

“He’s still young. He (will) learn what it takes to play a 162-game season — how not to injure himself, I guess, is the best way to put it. … Still, that doesn’t help us now, where he can’t play. We’re obviously a much better team when he’s in the lineup. I don’t think anyone would dispute that. So he needs to do something where he can play more often.”

Zimmerman delivered the last part of his critique with a smile, chuckling at its obviousness. The 28-year-old is nearly a decade older than Harper, with enough major-league experience to know that good health is not an accident. Harper possesses strength and athleticism in spades, but that is not enough. Body control is paramount. Rizzo believes Harper — who played only 130 games in the minors — will learn to conserve his energy as he gains more professional experience.

“He’ll learn,” Zimmerman said. “He already has learned and changed a little bit. The key to this game is being on the field, whether it’s a two-week time where you’re doing bad or a two-week time where you’re doing great. To stick around and become a great player, you’ve got to play.”

Major League Baseball probably would love to hype a head-to-head showdown between Harper and Machado, 20, in this week’s Beltway series — in the same way that the NBA playoffs so often become character dramas through confrontations between elite players. But the fluid in Harper’s knee halted the marketing effort before it could start.

Machado, who is hitting .332 and doubled home a run Wednesday, said he’s disappointed Harper won’t play in the series. They have never opposed one another in a regular-season professional game. “I definitely want to see him out on the field,” Machado said. But when I asked Machado about the suggestion that Harper needs to slow down, he looked at me incredulously.

“For what?” Machado said. “I love how he plays the game. He plays the game hard. That’s what you want on your team. You want somebody who’s going to do whatever they can to win. That’s what he brings to the table every day.”

Harper holds sacred that complete, consistent effort Machado extolled. That’s why, when listing players he admires, Harper started with Pete Rose and George Brett. Harper also mentioned Cal Ripken Jr., the ultimate combination of toughness and grace. And Harper did so while his Nationals teammates prepared to play in the ballpark where Ripken punched the clock for so many of his record 2,632 consecutive games.

Harper, a fervent student of baseball history, surely would appreciate the significance of playing 1,000 or even 500 games in a row. But he’s nowhere near that now. Harper’s odometer is on 0 — and I’m beginning to wonder how high his pulsating energy will allow it to go.