Junior Gotti may claim he’s out of the mob life, but his 24-year-old son is a hit man.

John Gotti III is set to make his professional mixed-martial-arts debut Friday night with a welterweight bout against Johnny “The Wild Child” Adams at the 3,500-seat Twin River Casino in Lincoln, RI.

The handsome hardbody will enter the octagon on what would have been the 77th birthday of his grandfather, “Dapper Don” John Gotti Sr., who died in prison in 2002.

The match isn’t a stunt or sideshow. For Gotti, it’s the culmination of three years of training and a 5-1 run on the New York amateur circuit.

“This kid is real. I believe you are looking at something very special here,” said the match’s promoter, Jimmy Burchfield Sr. “He’s built like Superman. You can see the agility and speed that he has. He’s equally talented standing up as on the mat. He’s got a very low-key personality.

“He’s surely not any kind of a wiseguy,” Burchfield said, oblivious to the pun.

The veteran pitchman said he could have “promoted the s- -t” out of the fight off the Gotti name, but explained that he respects the family’s wishes to stay under the radar. The family “wanted no special attention” and passed on having the debut bout televised.

The Gottis declined to be interviewed, but Junior Gotti relayed to The Post that his son “has to stay focused on his training . . . God willing, things will go well.”

Some fathers and sons bond by playing catch or watching football. For Gotti and his dad, it was boxing and MMA.

Watching the bouts was a way to make up for lost time after John “Junior” Gotti Jr. returned home from a six-year prison stint for racketeering in 2004. They would take in matches on TV at home in Oyster Bay, LI, or Junior would take his preteen son to tournaments in New Jersey.

Young John grew to be a 6-foot, 250-pound bodybuilder and briefly boxed. But his love of MMA stuck with him, and he began to reshape his body and mind for the cage.

He is now a sleek 179 pounds, with nine more to lose by this week’s weigh-in.

He doesn’t drink or smoke, “eats super clean,” and works out three times a day, five days a week, say his handlers. He has three trainers: Derek Panza, for boxing and kickboxing; Anthony D’Angelo, for submission/grappling, and Mike Kamp, for strength and conditioning.

His daily routine consists of wrestling and jiujitsu in the morning, strength and conditioning in the afternoon, and “in the evening either a yoga class or extra stretching and recovery workout,” Panza said.

“He’s right on target. He’s at 5 percent body fat,” Panza said.

The former kickboxing champ says Gotti is “quiet and to himself. A typical fighter. A bit of a loner,” but he has a “ferocity and passion for the actual art of combat.”

Gotti’s equally inexperienced opponent, the Vermont-bred Adams (0-1), could not be reached for comment. But one of Gotti’s amateur opponents hinted that Adams could get whacked — on the mat — if he doesn’t watch out.

“The guy was a warrior, man,” recalled Nick Panebianco, who was knocked out in the second round of their 2015 match. “Stone-cold face coming in, looking to do his business. He was a man with a mission. He never backed down or backed away.”