PORT ST. LUCIE -- MJ Melendez has played several positions over his major league career, but center field isn't among them.

To strengthen his résumé, the 27-year-old received action in center field this offseason in winter ball.

It leaves the Mets with another option beyond Tyrone Taylor to back up Luis Robert Jr.

It's also possible that rookie Carson Benge, who has a chance to crack the roster this spring, will see occasional action in center.

"I knew center field was something I wanted to implement into my game and it's something that now I feel comfortable that I can do, playing all three outfield positions," said Melendez, who arrived last week on a one-year contract worth $1.5 million.

Last season was a difficult one for Melendez, who was optioned to the minor leagues with the Royals during an April slump.

He returned for just 13 plate appearances for the season's remainder.

Melendez finished with a .321 OPS in 23 games.

"It was definitely tough -- not anything that I expected," Melendez said. "Being optioned was something I hadn't experienced in the past, so it's definitely something different. I feel like I was able to learn from it physically, mentally, emotionally and I think it will definitely be better moving forward."

The Mets experimented with the ABS challenge system during live batting practice, with catching instructor J.P. Arencibia as the plate umpire.

Teams will get two challenges of balls and strikes per game (with retention of a challenge when a call is overturned) beginning this season.

The system will be unveiled during the exhibition season.

"Everybody is going to be free to challenge," manager Carlos Mendoza said. "If they want to challenge, go ahead, but we are going to start tracking who is right, and then we'll come up with some guidelines. Right now, it's pretty fluid."

Nolan McLean threw 44 pitches over three ups in live batting practice.

The right-hander is ahead of most Mets pitchers this early in camp as he builds up for the World Baseball Classic.

MJ Melendez 'comfortable' with outfield versatility after winter ball...