Law enforcement authorities anticipate a possible assassination attempt against the Staten Island man suspected of gunning down mob boss Francesco “Franky Boy” Cali, sources told The Post on Sunday.

Officials haven’t confirmed that the Gambino crime family has posted a bounty on Anthony Comello, but “the general feeling is that there’s an ‘X’ on this guy’s back,” one source said.

“He’s going to have some issues in jail,” a high-ranking NYPD official said.

“Maybe there’s some guys who are wiseguys in jail who will show their allegiance to the Gambinos and say, ‘We’ll take care of this guy.’ ”

Sources said Cali’s gangland cronies would likely wait until Comello, 24, was serving time in an upstate prison before making an attempt on his life.

But that wouldn’t prevent another inmate from taking matters into his own hands to try to score a reward or simply to boost his reputation behind bars, sources said.

Comello is locked up in New Jersey’s Ocean County Jail pending charges in Wednesday night’s fatal shooting of Cali, 53, outside his home at 25 Hilltop Terrace in the Todt Hill section of Staten Island.

Investigators believe the execution-style slaying may have been revenge for Cali preventing his niece from dating Comello, sources have said.

Cali was shot 10 times after being lured outside by a killer who used a pickup truck to intentionally ram the Mafia don’s parked Cadillac Escalade SUV.

Comello, a construction worker, was tracked down and taken into custody Saturday at his family’s waterfront vacation home in Brick Township, New Jersey.

Once he arrives in the Big Apple, city correction officials will likely ask Comello, “Do you want protection? Do you feel threatened?,” a source said.

“If he does, they’ll put him in segregation. They might just do it anyway just out of an abundance of caution,” the source added.

A former city correction officer said Comello could either be held in protective custody, or in a jailhouse medical unit, as was done with infamous “Son of Sam” killer David Berkowitz.

“We are concerned for [Comello’s] safety but we deal with high-profile prisoners every day, and we make whatever arrangements are necessary to protect them.”