Newsday reporter Tim Healey spoke about the first official day of spring training for the Mets on Monday, Feb. 10, 2020. Credit: Newsday / Tim Healey

PORT ST. LUCIE, Fla. — Among the sources of optimism that emerged on the Mets’ first official day of spring training Monday, as pitchers and catchers reported to camp and many of them engaged in an informal light workout, was an area in which they have been terrible for years: relief pitching.

The Mets’ bullpen had a 4.99 ERA last year, a bottom-five mark in the majors and second worst in team history behind the inaugural 1962 Mets. Ranking right behind the 2019 team: the 2018 Mets (4.96 ERA) and the 2017 Mets (4.82).

So bad bullpens are not a new problem for the team, but they think they fixed it this time.

“We have a great bullpen,” Edwin Diaz, the closer most of last season, said through an interpreter. “If we’re healthy, we’re definitely going to be one of the best bullpens in the league.”

Added catcher Wilson Ramos: “It’s going to be good. Those guys throw the ball good. They got good talent. I know last year was a little bit of a] struggle but 100% sure those guys worked really hard this offseason to come back healthy and strong, and that will be good for the team.”

General manager Brodie Van Wagenen’s bullpen renovation was minimal but straightforward: Add one major-league reliever — Dellin Betances, a perennial Yankees All-Star who pitched in only one game last season because of injuries — and look for immense internal improvement.

That means the bullpen is built on ifs: if Diaz can greatly improve from his 5.59 ERA in 2019, if Jeurys Familia can rebound from the worst year of his career, if Betances can be his regular self after dealing with shoulder, lat and Achilles injuries, if Seth Lugo and Justin Wilson can repeat their strong 2019 seasons, and so on.

In the cases of at least Diaz and Familia, the fickle, sometimes pendular nature of year-to-year reliever performance could work in their favor after poor seasons.

For Diaz, who a year ago was a high-profile offseason addition from Seattle, the hope for improvement stems from his work with the Mets’ performance staff, including visits to Puerto Rico by a nutritionist, physical therapist and strength and conditioning coaches. He also received tips from Hall of Famer Pedro Martinez, a special assistant in the Red Sox front office.

“I feel healthier, I feel more energy,” Diaz said. “I feel really good going into this season. I have good vibes about it.”

The change for Familia is easier to see — and downright obvious when you see him. He said he has dropped 30 pounds since the end of last season, when he weighed about 270, thanks to a winter routine of “working hard and eating right.”

Being slimmer helps with balance on the mound and finishing pitches, he said.

“I was really overweight,” Familia said through an interpreter. “Most seasons, I would be around 240, 245. I didn’t realize I had gotten that far overweight, so I just wanted to come back and be the same weight I was for the rest of my career.

“It was really a lot of Dominican food. So it was like the rice, the fried chicken, all that stuff, all the good stuff that you had to cut out.”

Luis Rojas, in his third week as Mets manager, hasn’t named a closer yet. Is Diaz open to not being the closer?

“I’m open to helping the team win,” he said. “So if Luis tells me I have to come in in a certain inning, I’m open to doing that, as long as it’s helping the team win.”