PORT ST. LUCIE, Fla. — Four years ago, in the spring leading up to his big-league debut with the Royals, MJ Melendez was considered one of the best left-handed-hitting prospects in all of baseball.

Melendez had just led all of minor league baseball with 41 home runs in 2021. Fans in Kansas City were buzzing about his potential with soon-to-be superstar shortstop Bobby Witt Jr. also set to embark on his rookie season.

To say Melendez has fallen short of expectations since then would be an understatement. By the numbers, both in Melendez’s production and his big-league playing time, it’s been a steep decline in that span. He’s rattled off disappointing seasons in succession and dipped to a new low in 2025.

Melendez hasn’t stopped believing in himself, though. And according to the 27-year-old, the Mets feel the same way. That’s the main reason why he ended up at Mets camp this spring, signing off to compete for an Opening Day roster spot after agreeing to a one-year deal in free agency.

“I’ve had conversations with [the Mets] and saw that they definitely believe in me,” Melendez told NJ.com at Clover Park on Friday. “I definitely want somebody who has that same kind of thought process as me. I’m excited for a fresh start, excited for what’s to come and excited to get to learn here.”

Melendez spent most of last season in Triple-A with the Royals, batting .083 in his limited sample with the big-league club. He’s a career .215 hitter with 52 home runs and a sub-.700 OPS over 435 career games. The holes in his swing, the brutal defensive metrics and the inconsistent production cast an ominous cloud over the flashes of his potential in a Royals uniform.

“Obviously I would have liked to have been more consistent in the past,” Melendez said, “but everything happens for a reason. I feel like that’s led me here. I know I’m still very, very young in this game and can show the version of me that I feel like has yet to be unlocked.”

This is a classic change-of-scenery situation for a player trying to revive his career in a new uniform. The Mets like Melendez’s versatility — the fact that he can play outfield, first base and be an emergency catcher — plus his upside offensively. If he can swing the bat well this spring and show that he’s improving on defense, his chances to break camp will grow. Melendez said the Mets’ hitting staff has already made a great first impression, introductory conversations that have been “nothing short of amazing.”

“I think there’s more in the tank,” Mets manager Carlos Mendoza said. “He’s coming off a couple of down years, but I remember when he first came up to the league, he was a pretty good player. He’s gonna get an opportunity here and I’m excited to have him.”

While he does have a shot to prove himself, the chase for a roster spot is also largely out of Melendez’s control. Assuming Francisco Lindor is ready for Opening Day after his hamate bone surgery and Carson Benge ends up on the big-league roster, there’s only one spot available on the Mets’ bench. Fourth outfielder Tyrone Taylor and backup catcher Luis Torrens are locks with Mark Vientos profiling as a bench bat. If that’s the case, the Mets could opt for a utility infielder to occupy that final spot. Ronny Mauricio and Vidal Bruján would be the favorites there. Then again, having a left-handed bat with some pop on the bench, in Melendez, would also be valuable as Vientos, Taylor and Torrens are all righties.

None of that matters if Melendez fails to show the Mets that he’s capable of consistent production. To do that and show he’d help this team, Melendez isn’t trying to reinvent himself. He’s striving to tap into what was working when he was slugging in the minors and climbing prospect charts all those years ago. Between that mindset and the lessons he’s learned over those “frustrating” seasons in Kansas City, Melendez is oozing confidence.

“I’ve shown that I can have some positive production and definitely be an impact player,” he said. “It’s just about continuing to unlock that consistency, but not try to make me into somebody that I’m not. Let’s build off of the positive things I do, like even getting back to some past videos of what made me successful. I’m not trying to change that. I want to go and continue to better that.”