Manny Pacquiao would knock Conor McGregor out inside three rounds, according to the Filipino’s conditioning coach.

A crossover bout between the two combat sports stars has been muted ever since McGregor was stopped in the tenth round by Floyd Mayweather Jr three years ago.

And Pacquiao’s conditioning coach Justin Fortune believes it would take the 41-year-old considerably less time than Mayweather to knock McGregor out in a boxing ring.

Speaking to the Manila Times, he said: "Why even make that guy rich?

"And it won’t do absolutely anything for Pacquiao as far as his legacy [is concerned].

"Remember, this is just my opinion. Manny goes down as the greatest fighter in history when he finishes because no one has done what he accomplished in boxing.

"Why destroy your legacy for a bum like McGregor?

"Manny will destroy Conor McGregor inside the three rounds. He will obliterate him too fast and too strong as an amazing fighter. McGregor is nothing."

Pacquiao, who also lost to Mayweather back in 2015, currently holds the WBA Welterweight Title and has come out victorious in each of his last three bouts.

However, as he continues to attempt balancing boxing and being the governor of the Philippines, he has not fought since July 2019.

Meanwhile, McGregor announced his retirement from combat sports during the coronavirus lockdown.

His last fight back In January lasted just 40 seconds as he crushed Donald ‘Cowboy’ Cerrone at UFC 246.