The Nationals got Bryce Harper back on Monday night, but his pregame comments seemed to suggest he wasn’t too happy being in left field or sixth in the batting order. (Katherine Frey/The Washington Post)

Monday was supposed to be a party for the Nationals, the night Bryce Harper became the final returning piece of their injured roster, the team intact for the first time all year. It was even Harper Bobblehead Night with 10,000 extra fans on hand, some lining up five-and-a-half hours early for the figurine.

Instead of “Nothing But Natitude,” Harper’s box could’ve read, “Nothing But Attitude.” The 21-year-old exposed the fissures that have gotten more public between the young star and the Nats. Being back in the Nats’ lineup after two months wasn’t enough for Harper; he wanted to write the lineup, too.

Manager Matt Williams put Ryan Zimmerman at third base, Anthony Rendon at second base, Harper in left field and benched Danny Espinosa. He also batted Harper sixth, exiled from the glamorous heart-of-the-order spots. Harper disagreed, on all fronts, and said so several hours before the game.

“I think [Zimmerman] should be playing left. Rendon’s a good third baseman. He should be playing third. We’ve got one of the best second basemen in the league in Danny Espinosa,” said Harper. “Of course, we want the best-hitting lineup in there. [But] I think Rendon playing third and Zim playing left is something that would be good for this team. I think that should be what’s happening.”

This Harper proposal would also put Denard Span on the bench and Harper himself in center field, the position he’s politicked for weeks to play. Williams has talked about daily designer lineups, constantly changing. Harper’s suggestion amounts to a fixed lineup — to his advantage. If Harper were 10 years more established in deeds, not dolls, it’d be audacious to manage a team after being on the DL for more than half of the Nats’ previous 193 games. But to do it with one homer halfway into a season?

Anything else? How are those internal lines of communication working?

“I haven’t talked to nobody about anything, so I have no clue,” said Harper, who frequently mentioned how happy and excited he was to return but never smiled. “I know I’m playing left tonight, via Twitter. So I guess that’s where I’m going.”

And what about batting sixth?

“I’m in the lineup. That’s all that matters. If I had the lineup, it would maybe not be the same. He’s got the lineup card. He’s got the pen. That’s what he’s doing,” said Harper. “So there’s nothing I can do about it. I’m hitting sixth tonight.”

So, the manager has three players out of position, the wrong guy benched, Harper batting in the wrong spot and he has to learn about this stuff on Twitter.

“Hopefully, nobody kills themselves trying to get a bobblehead,” said Harper, who knows just how central Nationals marketers have made him to the franchise’s merchandising identity.

Williams, told the views of his young assistant manager, said tersely, “Happy to have him back. When he’s out there, regardless of where he’s at, we’d like him to catch it when it’s hit to him and hit it when it’s thrown to him. . . . I don’t have any comment other than that. . . . Hopefully, I can write his name in there every single day the rest of the year. That would be very important.”

“Mutiny on the Bounty” had less plot. And more plot is just what the Nats don’t need.

Harper, the healthy player, is a key answer for them. He singled in their first run, took an extra base on an outfield bobble and made two cannon throws that nearly resulted in outs as the Nationals handled the Rockies, 7-3. He’s just what the Nats need. . . .

. . . except when a team has nine everyday players for eight positions, and all — except one — are pulling in the same direction, the odd man is always going to be out. Teammates are already torn between their appreciation for Harper’s hard work and his willingness to attract every iota of attention even though his feats — such as two sub-60 RBI seasons — are still as much about potential as production.

General Manager Mike Rizzo flies to defend Harper’s performance on the field. “He has not had two ‘good’ seasons,” Rizzo said last week. “He has had two great seasons — comparable to anything any player has ever had at 19 and 20 years old.”

As a counterpoint to any Bryce critiques, when Harper hit three home runs on Saturday night in a rehab game for Harrisburg, he was still the youngest player on that Class AA team.

All season there has been a submerged struggle between Harper and his bosses. Starting with the opening day lineup, when he batted fifth, to being yanked from an April game for not hustling by rookie manager Williams, the Nats have tried to prod Harper, in his third season, to rein himself in. Not a lot. Just a sign, please.

In recent weeks, as Harper rehabilitated his surgically repaired left thumb, the Nats and their two-time all-star were seldom on the same page. After Harper had said he would not “rush back” and might not return until after the All-Star Game, Williams immediately ran a provisional July 1 return date up the flag pole. Harper repeated all his reservations — “if it’s weeks, it’s weeks.”

Nats players are aware of the irony that a commercial campaign for Gatorade has run nationwide for many weeks with Harper, depicted as a bionic super-machine, hawking the product at the same time that the human Harper has only one home run this season.

Ballplayers sympathize with injuries. But you’re still expected to understand that, to be a great player, you first have to play — almost every day. And until you do, you can’t act like you already have.

Big league teams have tried to figure out how to mold young potential superstars into actual stars for generations. And those young players have had to grow up, figure out their role, under scrutiny. The spotlight on Harper is greater than the cacophony around a 21-year-old Mickey Mantle because population and information platforms have grown. But it was always astronomical and often warping.

There’s little doubt the Nats sincerely want Harper to be a more mature teammate and more polished player. But it’s also likely they wish he’d conform, tone down his flamboyant act and fit more smoothly with a vet clubhouse that embraced and mentored him for two years but now expects more. Are they trying to train, but not break a young stallion, much as the Dodgers have tried to figure out Yasiel Puig? And was a manager nicknamed The Big Marine hired with that one thought in mind?

The business side of the Nationals, and MLB as well, promotes Harper relentlessly as a symbol of their franchise and one of the faces of the game. Meanwhile, the Nats’ baseball side tries, as it would with any player, to make sure that clubhouse prerogatives and attitude are aligned. It’s a tough balance.

Harper needs to grasp that the simplest explanation of the Nats’ lineup plans is probably correct: This is what the team imagined all winter and put on the field, position for position, on opening day.

Only 80 more lineups to go. It is Harper’s job to be in them, not make them.