New York Mets pitcher Steven Matz throws a live batting...

New York Mets pitcher Steven Matz throws a live batting session on Sunday, Feb. 28, 2016 during a spring training workout in Port St. Lucie, Fla. Credit: Newsday / Alejandra Villa

PORT ST. LUCIE, Fla. — Frank Viola took the microphone last week and made his declaration, one that drew applause from a crowd of Mets fans gathered at a local pub to hear him speak.

His prediction: Despite plenty of hype surrounding the Dodgers’ brilliant young shortstop, Corey Seager, it will be Steven Matz who wins the National League Rookie of the Year award this season.

“You heard me the other night, didn’t you?” said Viola, a former Cy Young Award winner and the Mets’ Triple-A pitching coach. “I’m going to stick with it. I think Corey Seager is a hell of a ballplayer. But this kid [Matz] has the tools. The last thing I want to do is put pressure on a kid. But he’s got the tools and the makeup to win that award.”

If anyone would know, it’s Viola, whose connection with Matz goes beyond their shared Long Island roots. During their years with the Mets’ organization, they have established a strong working relationship.

“For me, he really was all about the mental part,” said Matz, a Stony Brook native. “He instilled the confidence in me coming up, my first full season.”

In 2013, Matz pitched for Class A Savannah. Viola was his pitching coach. That season proved key for Matz, who was drafted in 2009, only to have a bumpy rehab from Tommy John surgery delay his pro debut until 2012.

“Having the 15 years of experience with big-league pitching, you know the telltale signs of stuff that a kid needs to work on,” said Viola, a native of East Meadow. “Steven, the mental part was really putting a routine together in the early stages of his career. Every time out, he’d throw a different side [session]. He wouldn’t have a rhyme or reason for what he was doing. We talked through that.”

The Long Island lefties again were reunited in 2015 with Triple-A Las Vegas, a pit stop that Matz used to vault his way into the Mets’ starting rotation in late June. By then, it was clear that Matz was physically ready to make the jump.

“It was just trying to groom him to fine-tune that routine, knowing what pitch to throw at what time, and those certain little things that a lot of kids don’t understand,” Viola said.

Matz, 24, went 4-0 with a 2.27 ERA in six major-league starts but was shelved for nearly two months with a torn lat muscle. He returned late in the season, then had back problems that threatened to sideline him for the postseason. But Matz fought through them and posted a 3.60 ERA in three postseason starts, including one each in the NLDS, NLCS and World Series.

“There’s so much more in the tank,” said Viola, noting his mid- 90s fastball, a rarity for lefties.

Throughout their relationship, Viola said he has not shied away from challenging Matz. That includes declaring that Matz will be named Rookie of the Year if he stays healthy enough to make his starts.

“His makeup is incredible, off the charts,” Viola said. “You challenge him and he’ll be up to it. Other kids you say that to and they’ll shut down, or they’ll try to do more than they’re capable of doing. He knows how I feel about him.”

Matz didn’t sound surprised when informed of Viola’s bold prediction. “I think he’s a little biased,” he said with a laugh. “But hey, I’m glad he’s got confidence in me. He always has. And that’s what he’s kind of instilled in me is having confidence in myself as well. It’s a great compliment.”

Steven Matz will try to join these Mets pitchers who were voted NL Rookie of the Year:

Pitcher Year W-L ERA

Tom Seaver 1967 16-13 2.76

Jon Matlack 1972 15-10 2.32

Dwight Gooden 1984 17-9 2.60

Jacob deGrom 2014 9-6 2.69