A.J. Burnett has not allowed more than two earned runs in any of his first eight starts this season. The Pirate right-hander starts Saturday against the New York Mets.

PITTSBURGH — The fire is still there, churning away somewhere inside A.J. Burnett’s well-tattooed and teenage-thin body. The flames, however, are simply better hidden.

Instead of the five-alarm outbursts that would accompany adversity earlier in the veteran pitcher’s 17-year career, you’ll only get a flicker or two.

There is an air of serenity surrounding Burnett these days. His first eight starts for the Pittsburgh Pirates in what he says — for now anyway — is his final season have been mini masterpieces, a study of a man at peace with himself and his game.

The 38-year-old is 3-1 heading into a showdown with New York Mets resurgent ace Matt Harvey on Saturday, and his 1.38 is second in the majors. Burnett looks very much like a guy in the middle of his prime rather than sprinting toward retirement.

“He’s totally comfortable with who he is,” Pirates pitching coach Ray Searage said. “What you’re seeing is someone who has been through every wringer this game can dish out to you and come out the other side.”

Burnett’s arrival in 2012 in a trade with the New York Yankees signaled a pivotal moment in Pittsburgh’s escape from mediocrity. He won 26 games in two seasons, serving as the unquestioned ace on a largely unproven staff. His return last winter after an ill-fated year in Philadelphia — where he led the NL losses, earned runs and walks while dealing with a hernia — was one more unorthodox move for a guy who enjoys bucking convention.

He wasn’t kidding when he said he left $4.5 million on the table with the Phillies to make a legit run at a championship in Pittsburgh. So far, he has more than held up his end of the bargain, serving as one few constants on a team that has spent the first quarter of the season devoid of rhythm or any real identity.

“I mean some things are going good,” Burnett said. “Plays are being made. Guys are playing hard. I’m making a pitch here or there, but it’s a funny game. You can go out there and make pitches and not get the results you want. So it’s just a matter of trying to go at them and stay aggressive as much as you can.”

Or as much as his stuff allows. Burnett no longer tries to outmuscle opponents as much as he tries to outthink them.

He spent years relying heavily on a couple of pitches. He’s added a series of variations on his breaking ball and no longer eyes a change-up the way a 6-year-old eyes his lima beans, as something to be endured every once in awhile so he can get to the good stuff. Making the transition from thrower to artist can be difficult.

Josh Beckett, Brad Penny, Carl Pavano and Dontrelle Willis — fellow hard-throwing young guns on the Marlins early in the millennium — are either retired or looking for work. Not Burnett, who is currently 40th on the all-time strikeout list (2,413) and could crack the Top 30 by September if he stays healthy and effective.

Yet Burnett is no longer peeking up at the K’s that pile up on the ribbon board around PNC Park. He’s grown to accept the game’s changing dynamics. The same player who had no problem airing his distaste of defensive shifts as late as two years ago now seems more willing than ever to let the other eight guys on the field with him do some of the work.

“Some guys will say `I’m going to stay the way I am.’ He made the changes when he knew he had to,” Searage said. “He’s very realistic about his abilities.”

And almost Zen-like in his ability to let go of the past. Where mistakes would once eat at him, Burnett now resets every time he receives the ball from the catcher.

“If he gets into hairy situation, if he gives up a run, it doesn’t matter,” Searage said. “He holds true to execution of the next pitch.”

Still, some things don’t change. They can’t if Burnett is going to be Burnett, the Batman-loving, Zombie Apocalypse ready kid who is also a mentor to ace-in-training Gerrit Cole and erratic Jeff Locke. While Burnett and Searage have a relationship built on mutual respect, there are times when the anarchist in Burnett still comes out and he’ll shake signs until he gets what he wants no matter the game plan. That’s fine by Searage.

“I’d rather have that conviction behind that pitch and take whatever comes ,” Searage said.