New York Mets general manager Brodie Van Wagenen speaks to...

New York Mets general manager Brodie Van Wagenen speaks to the media prior to a game against the Washington Nationals at Citi Field on May 20 in Queens. Credit: Jim McIsaac

MIAMI — Having constructed the roster with the second-worst record in the National League, Mets general manager Brodie Van Wagenen opened the second half of the season Friday by acknowledging the obvious: His team is a trade-deadline seller.

The Mets already have gotten “an overwhelming amount of incoming calls” about their players, Van Wagenen said. But he indicated the team’s activity leading up to the July 31 trade deadline will be centered around players with expiring contracts, a group that includes Zack Wheeler, Todd Frazier and Jason Vargas (team option/buyout for 2020).

Van Wagenen said he expects Noah Syndergaard, Jacob deGrom and other players under team control to remain with the Mets as the organization looks to tweak — not completely overhaul — its personnel in an attempt to contend in 2020.

But that hardly lessens the sting of a bad 2019 for Van Wagenen and the Mets. The rookie GM’s now-infamous preseason beckoning of the NL East to “come get us” now has a summer sequel.

“They came and got us,” Van Wagenen said in the visitors’ dugout at Marlins Park. “We are incredibly disappointed.”

Don’t expect wholesale changes this month, though.

Van Wagenen said he still believes the Mets, out of the playoff race by July for the third season in a row, have the core of a team that can compete for a postseason spot. But whereas that core was built around the rotation last winter, it now includes the likes of All-Stars Pete Alonso and Jeff McNeil and other players the Mets didn’t know they could count on.

“We feel like we have a core going forward, just maybe of a different core,” said Van Wagenen, who also mentioned first baseman/leftfielder Dominic Smith by name. “We have a core from which we can compete, and we’ll look at our moves with both win now or certainly win in 2020 [goals] and looking beyond that. I don’t anticipate being in a situation where we’d have a total teardown rebuild at this point.”

The past two years, the Mets prioritized dumping salaries over getting better prospects during their midseason sell-offs. Van Wagenen did not commit to changing that approach this year.

“We will be open-minded and look for the best opportunities to improve,” he said. “And whether that is in terms of money or whether that is in terms of talent, we’ll have to evaluate those cases [one at a time].”

During Van Wagenen’s 23-minute news conference, his first wide-ranging public comments about the state of the team in several weeks, he downplayed a lot of the negative realities and perceptions that surround his team.

He didn’t offer any tangible lessons learned from last offseason — since which nearly none of his moves have worked — but said he preferred to wait to evaluate after the season. He attributed his chair-throwing during a postgame meeting with coaches last week to frustration with another blown late lead, emotions he knows fans share.

“I’m not typically throwing furniture,” Van Wagenen said.

He admitted that marquee offseason additions Robinson Cano and Edwin Diaz have been disappointing but said, “Both players have 72 games in front of them to change the narrative.”

Does Van Wagenen consider this season to be on him? “I think any time a team struggles, it’s on the organization,” he said, later adding, “I accept my responsibility.”

For the next 2 1⁄2 months, the come-get-us Mets will be “underdogs” with “low expectations.”

“We view ourselves as the underdogs,” Van Wagenen said. “In the second half of the year, I think we have low expectations for what we can be, and I think now we’ll take the underdog role and run with it and try to prove some people wrong this year and certainly try to improve upon it next year.”