Travis d’Arnaud was once a top prospect. The key piece in the R.A. Dickey trade back in 2012.

The catcher has not lived up to those high expectations since debuting in 2013. However, he realizes he must prove he is a valuable member of the Mets.

According to Kevin Kernan of the New York Post, d’Arnaud is ready to silence the critics and “unlocked” the key to his swing in September last year.

“I feel like I always have something to prove,’’ he said. “There’s always doubters. I just want to prove people wrong. And this year I’m really excited.’’

The 29-year-old is set to split time behind the dish with Kevin Plawecki, as the team looks to get the most production out of their backstops.

D’Arnaud hit to a .244/.293/.443 clip overall last year, but in September when he said he revamped his swing, he hit .297/.343/.656. He attributes the success to keeping his eye on the ball as well, a tip given to him by former hitting coach Kevin Long

“It’s weird,’’ d’Arnaud said. “All I have to do is keep my eye on the baseball. If I pull my head at all, my natural loft swing cuts off because my body can’t get through.’’

This winter, he took a trip down to Arizona to meet with hitting coach Pat Roessler, who worked under the tutelage of Long the last few seasons.

“Every swing now, even off the tee, I just keep my head down,’’ d’Arnaud said. “K-Long told me in the beginning of September, ‘Let the crowd tell you if it’s gone, you don’t need to see it.’”

When asked about splitting time with Plawecki, d’Arnaud said they are close friends and think they will jive well together, especially defensively.

“Kevin [Plawecki] and I work so well together,” d’Arnaud said. “We’re very open about what we see in pitchers.’’

D’Arnaud also commended Mickey Callaway for his experience working with pitchers and said it will be nice to have another great set of eyes on them.

For the now veteran catcher, the key is staying on the field. He appeared in 112 games last year, but again missed time due to injury. He is a free agent after the 2019 season, so he has the next couple years to prove himself and that he can be a quality catcher in the majors.

“It’s a fresh start,’’ d’Arnaud said. “It will be a fun year. I’m going to continue what I did in September. I have a lot of confidence.’’