DENVER — Amed Rosario has been guided through his first few days in the big leagues by his unofficial chaperone, Jose Reyes, who himself has lived through being the shiny-new franchise shortstop of the future.

Of all the pieces of advice that have been shared during Rosario’s whirlwind introduction to the majors, one will loom large on Friday when the 21-year-old phenom makes his Citi Field debut.

“He seems relaxed, for now,” Reyes said Thursday, before the Mets’ 5-4 loss to the Rockies. “But I told him when you get to New York, it’s going to be a different energy, a different atmosphere. I think it’s going to be fine.”

By the time Rosario arrives at Citi Field, he will be the veteran of three big-league games. He’s already crossed his first hit off his to-do list.

And he’s even endured the first sting of reliving a tough play at a critical moment of a game. Rosario’s highly anticipated debut on Tuesday was capped by a hard-hit grounder that he failed to backhand, partly because he was moving in the opposite direction to cover second base.

At his locker following the game, a contingent of about half a dozen media members awaited. In New York, that number would have been tripled.

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“I think I have a decent idea of what’s going to happen tomorrow,” Rosario, who tripled Thursday for the second time since being called up, said through a translator.

For the first time, members of his family will be attendance. The contingent will include three of his sisters and his father.

“I’m very excited to play at home tomorrow just because my family’s going to be there,” Rosario said. “And I think that’s a dream.”

Hoopla won’t be in short supply at Citi Field on Friday. The Dodgers are a star-studded juggernaut with a new toy of their own in Yu Darvish. The ex-Rangers righthander was acquired right before the 4 p.m. trade deadline on Monday. His Dodgers debut comes against the Mets.

Reyes recalls a similar experience leading up to his own home debut at Shea Stadium back in 2003. Like Rosario, Reyes enjoyed the benefit of a soft opening of sorts on the road. His promotion came at the start of a road trip at Texas, followed by stops in Anaheim and Florida.

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By his home debut, Reyes had 10 big-league games under his belt. In retrospect, none of those could truly prepare him for the challenge that awaited: the beginning of a Subway Series clash with the Yankees.

“I never get nervous,” Reyes said. “But that day, my heartbeat was a little bit faster. After the first game, I was fine. But the first game, it felt like a playoff atmosphere. It was a little bit crazy for me.”

Indeed, he couldn’t get over playing a team he had kept tabs on growing up in the Dominican Republic. Back then, the roster of stars in pinstripes was headed by Derek Jeter. Looking back, Reyes was glad to face a stiff test early.

“Because you put that out of the way right away,” Reyes said. “You say ‘if I can go through this, I’ll be fine.’ For me, I like being in a pressure situation. I’m sure he’s the same way. He likes that. As a young player when they throw you in like that, it’s always good. You want to feel that little pressure, to say ‘Oh, this is it for me, let’s see what I’m made of.’ ”

Rosario’s home slate includes a three-game set against the Dodgers and two against the Rangers. Following four games in Philadelphia, the Mets return to New York on Aug. 14 for the beginning of the Subway Series in the Bronx.

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“He’s coming up and we’ve got two playoff teams in a row, and we have several coming up as a matter of fact,” manager Terry Collins said earlier this week. “It will be fun to watch him have to pick his game up against these guys because they’re certainly playing for something.”