The Red Sox's Rick Porcello pitches during the first inning...

The Red Sox's Rick Porcello pitches during the first inning of a game against the Yankees in Boston on Sunday. Credit: AP/Michael Dwyer

SAN DIEGO — As the Mets surveyed the pitching market — starters and relievers, free agents and trade targets — and considered their obvious rotation and bullpen needs, Brodie Van Wagenen’s experiences in his first year on the job influenced his decisions this week.

Relievers are volatile. Starters, less so.

And so the Mets followed up on their addition of Michael Wacha (one year, $3 million plus up to $7 million in incentives) by agreeing to sign another righthanded starting pitcher: Rick Porcello, who will get $10 million on a one-year contract, a source said Thursday. The deals are unofficial until each player passes a physical.

To fill their one hole in the rotation, the Mets added a pair of back-end arms in the hopes that it will benefit the bullpen, too.

“The volatility in the reliever market, which we experienced last year, makes investment into that market a little bit riskier,” Van Wagenen said Thursday as the winter meetings wrapped up at the Manchester Grand Hyatt San Diego. “We’re looking at a situation where we have six starters right now that all have fourth- starter-or-better ability. That value versus investing in more volatile relievers with checkered track records, we feel like this is the better way to go.”

Having six starters allows the Mets a degree of flexibility — say, moving one to the bullpen or another team to fortify another area of the roster — during the rest of the offseason and into spring training.

Van Wagenen said the Mets believe they have eight starters to bring into camp, counting Seth Lugo and Robert Gsellman. They have been relievers the past two seasons.

“We’re probably the deepest starting pitching rotation in baseball,” Van Wagenen said. “There was a lot talked about our lack of starting pitching depth over the course of the last couple of weeks. I think that story has changed.”

The team’s preference remains leaving Lugo and Gsellman in one role for the entire season as opposed to bouncing them between the rotation and bullpen, Van Wagenen said. So that Nos. 7-8 starter depth might disappear come regular season if everyone is healthy and Lugo and Gsellman are in the bullpen.

Porcello, who will turn 31 this month and grew up in New Jersey, joins the Mets after perhaps the worst year of his career, when he was last among qualified pitchers with a 5.52 ERA. Since winning the American League Cy Young Award in 2016, he has a 4.79 ERA and 1.32 WHIP.

But Porcello offers what Wacha does not: a track record of health. He has been on the injured list once in 11 seasons, averaging more than 30 starts per year.

The Mets think Porcello can be better than he has been in recent years, but Van Wagenen didn’t offer details on how.

“We believe that he knows what he wants to do. We want him to have a voice,” he said. “We want him to be able to pitch the way he feels like his skill sets play best. We have some ideas to help him do that and we’ll be working collaboratively and make sure he has the upside to be the Cy Young-type pitcher he has been in the past.”

Van Wagenen suggested that the Mets might not add any more relievers on major-league contracts. He cited Lugo, Gsellman and Brad Brach as going “back” to the bullpen, though they were all members of the 2019 unit that had a 4.99 ERA.

But you can be sure the Mets aren’t done yet this offseason.

“We have the ability to do ‘wants,’  ” Van Wagenen said, “now that many of our needs are filled.”