The Mets are no longer the little brother.

At least that’s what Mets broadcaster Howie Rose seemed to see after the club signed Juan Soto to a historic 15-year, $765 million contract on Sunday night.

Mets fans reveled in the glory following the news, and the team’s longtime radio voice took to social media to talk about the important moment in the context of the franchise’s history and reputation in New York.

“This is perhaps the most unique moment in New York Mets history,” Rose wrote. “I told you from day one that Steve Cohen wasn’t going to be the little brother in town. He aimed right at the Yankees and everyone else. It’s on.”

Rose wasn’t the only Mets broadcaster trying to put the moment in perspective.

During a hit on SNY breaking news about Soto’s signing, Gary Cohen described it as “the biggest, most important transaction the Mets have ever made.”

“The only one that goes in the same direction was the Mike Piazza trade in 1998,” Cohen continued. “The Mets have never delved deeper into the free agent market in terms of the caliber of players and youth. The closest thing to that would have been signing Carlos Beltrán, but Beltrán wasn’t yet 26 when the Mets signed him. Soto just turned 26.

“He’s arguably the best hitter in baseball, if not, he’s in the top three, and did I mention he’s just turning 26? He has seven years under his belt. He is a wonderful offensive player and completely changes the conversation surrounding the Mets.”

Soto’s decision was a huge moment for the Mets, as the slugger rejected a 16-year, $760 million offer from the Yankees, according to The Post’s Jon Heyman.

Soto is coming off a season in which he hit a career-best 41 home runs and helped the Yankees reach the World Series for the first time since 2009.