NEW YORK -- Before a recent batting-practice session at Citi Field, Mets chief operating officer Jeff Wilpon stood by the cage razzing Pete Alonso. He told the rookie that he’d seen Yoenis Cespedes and Albert Pujols hit home runs into Citi’s towering third deck, but that he hadn’t seen Alonso -- a player quickly becoming known for his prodigious blasts -- do the same.

“I’m like, ‘Yeah. OK. Yeah. All right,’” Alonso said Saturday, after crushing one off the facing of that third deck. “There you go.”

In accomplishing the feat, Alonso added another highlight to his banner rookie season. Alonso’s three-run blast in an 8-7 win over the Cardinals was the Mets’ longest home run of the year and the furthest of his young career. Statcast projected the ball’s distance at 458 feet, the longest by any Mets hitter at Citi Field since tracking began in 2015.

Facing Cardinals starter Michael Wacha in the first inning, Alonso crushed a 3-1 changeup 111.8 mph off the bat. It struck the facing of the upper deck, ricocheting down into the seats below. The monster shot eclipsed Alonso’s previous career long, a 449-foot home run at Petco Park in May, and easily outdistanced his best at Citi Field, a 427-foot shot against the Brewers in April.

“That one felt really good,” Alonso said. “That one felt really damn good.”

Equally impressive has been the volume of Alonso’s home runs. Saturday’s blast was his 23rd, giving him sole possession of second in the Majors, only three behind leader Christian Yelich of the Brewers. Only four players in MLB history -- Mark McGwire, Aaron Judge, Jose Abreu and Cody Bellinger -- hit more before the All-Star break in their rookie seasons. Alonso is within striking distance of passing most, if not all of them, on that list.

Alonso is also on pace to shatter the Mets’ single-season homer record of 41, set by Todd Hundley in 1996 and matched by Carlos Beltran in 2006. Alonso has talked frequently of his desire to participate in next month’s Home Run Derby in Cleveland, promising to donate a portion of the $1 million grand prize to charity if he wins.