Chris “Mad Dog” Russo isn’t sold on the Mets and went on the record predicting a sophomore slump for Pete Alonso.

During a Mets critique on his MLB Network “High Heat” show, Russo said Alonso “is not hitting 50 homers again” and that the team will have to figure out where it “will pick up a little of his offense.”

Alonso set the major-league rookie record with 53 home runs last season, passing the Yankees’ Aaron Judge.

The power-hitting first baseman told The Post’s Mike Puma on Thursday that he’s striving to be a better defensive first baseman and better all-around player.

“Keith (Hernandez) has got (11) Gold Gloves, he is a great first baseman, there is no denying that and I want to be as fine-tuned as he was when he was in the game,” Alonso said before a workout at Clover Park. “There’s a lot of responsibilities on that side of the diamond and last year I feel like I did a good job of learning on the big league level and now I want to be great.”

Chris "Mad Dog" Russo and Pete Alonso
Chris “Mad Dog” Russo and Pete AlonsoGetty Images; Anthony J. Causi

Russo said the “black cloud” over the Mets organization makes them a risky pick this season, citing the fact that they have made the playoffs just six times in the 33 seasons since their World Series title in 1986.

“I’m not picking the Mets to make the playoffs,” said Russo, who predicted the Amazin’s would win between 83 and 87 games. “Maybe that would do them some good because every time I pick them to go to the World Series … they go 82-80 and fire a manager.

“I just don’t think that they’re very good. You’re asking too many components to click,” he added. “Alonso, the top two in the rotation (Jacob deGrom and Noah Syndergaard), (Amed) Rosario, getting something out of center field. Maybe (Yoenis) Cespedes adds something. Will (Jed) Lowrie play a game, outside the seven at-bats that he got last year for $10 million bucks? I just don’t think the Mets … too many questions.”