MIAMI — One under-the-radar benefit to this World Baseball Classic, at least from a Mets perspective, began in earnest Thursday while the Dominican Republic took batting practice at Marlins Park. As Adrian Beltre vacuumed up ground balls at third base, Jose Reyes stood behind the five-time Gold Glove winner, watching intently.

Reyes was that night’s starting shortstop, a position he’s manned for 1,522 games in the majors. Reyes never had played third until the Mets signed him last season to be the replacement for his injured friend, David Wright. He still thinks of himself as a shortstop, but now that fate has nudged him about 45 feet to his right, Reyes is committed to the switch.

The move was immediate for Reyes, not long after pen touched paper on his new Mets contract. Handling third base, however, involves more than just standing on a different patch of dirt, even for a player with Reyes’ athletic ability. And that’s where Beltre comes in.

Beltre didn’t join the D.R. squad until Thursday, missing the first two exhibition games against the Orioles and Pirates, so Reyes didn’t waste any time getting started. After Reyes fielded a few dozen grounders at short, he slid over and went to school on Beltre, whose fifth Glove Glove came last season at age 37.

“I’m going to learn a lot during this WBC,” Reyes said, nodding toward Beltre. “It’s a great opportunity for me.”

After the third-base tutorial, Reyes was in midseason form, delivering three hits and a run scored in the D.R.’s 9-2 victory over Canada. Reyes led off the game with a double into the rightfield corner, then tacked on a pair of singles. He also had his first stolen base in the Classic since 2006 and third in 16 games overall.

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Jose Bautista had a booming two-run homer. Jeurys Familia got the final out by whiffing Josh Naylor with a fastball that registered 99 mph on the scoreboard. Hansel Robles struck out two and Dellin Betances pitched a scoreless eighth inning.

No team appears to have more fun at this tournament than the D.R., and Reyes, a clubhouse catalyst during the past three, usually seems to enjoy it the most.

That doesn’t mean he’s not serious about the games or what he might gain in the next two weeks, with the Dominican club a favorite to repeat after its undefeated title romp (8-0) in 2013. It’s why Reyes has latched on to Beltre for lessons that should pay off for the Mets once the WBC is over.

With Wright’s return further delayed by his recent shoulder setback and his long-term prognosis cloudy, Reyes should be a fixture at third for this upcoming season. He’s also the Mets’ only true leadoff man, and spelling Asdrubal Cabrera at short on occasion should keep him in the lineup when Terry Collins wants to give Wilmer Flores a shot.

Outside the lines, Reyes can be just as valuable. He quickly became tight with Yoenis Cespedes after only a few weeks on the team, and he tends to keep a roster loose, as he did during his first nine seasons in Flushing. Now that Reyes is back with his Dominican crew, he’s grown into a bigger leading presence and could be seen on an Instagram post giving a clubhouse speech before the team’s first WBC tune-up.

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Reyes wanted to stress the D.R.-first mission and emphasize that although it has a stacked roster with some of MLB’s top talent, it’s important to remember what’s on the front of the jersey rather than the back.

On that subject, Reyes doesn’t joke around. He’s the only member of this year’s Dominican team to have played in all four of the Classics, and 2013 was his best. He hit .314 (11-for-35) with a double, triple and home run in eight games.

“We are all united here for a reason, to win the championship for the Dominican Republic,” Reyes said. “We understand that there are many stars here on this team, but it’s not a matter of ego. It’s to go out there at 100 percent because we know we’re doing it for our country.”

Stroman vs. the D.R. In the most highly anticipated WBC matchup this weekend, former Patchogue-Medford star Marcus Stroman will start tomorrow night for Team U.S.A. against the Dominican Republic.