But while it is British heavyweight champion Julius Francis for whom Tyson is daily beating the heaviest punchbag ever housed at the Grosvenor Hotel it is the spectre of Lennox Lewis which you suspect occupies his every waking thought.
Lewis is in possession of the undisputed heavyweight belt which Tyson has vowed to reclaim for a record third time - a feat which would equal that of the legendary Muhammad Ali.
Lewis is the fighter with whom Tyson once sparred as a teenager and who he claims he knocked clean out of the ring on their first meeting.
"Did he ever tell you about it?" Tyson inquired of one questioner. "What did he tell you? Bang! Bump! Ask him. I knocked him right out of the ring."
Their path has crossed just once since - in a restaurant where Tyson was dining with his wife.
"He gave me one of those stares," recalls Tyson. "I was with my wife and I was trying to be a gentleman - which I'm not. I was trying to prove everything my wife thought about me was wrong and I did."
Not that Tyson plans to be so gentlemanly if and when the pair actually get in the ring together - a meeting Tyson yearns for in Britain later this year.
"He's a tough fighter," said Tyson. "But by the time I come to fight him I'll be prepared. We were supposed to fight since we were 15 years old and though we've never had a chance to fight for the world championship, it's pre-ordained."
Michael Grant doubts Lennox Lewis' powers of resilience ahead of their April 29 championship fight at Madison Square Garden.
The American has only briefly met Britain's undisputed world heavyweight champion, but claims Lewis is "a respectable man outside the ring, but maybe not marketable.
"I don't think he moves fast," said Grant. "His chin is questionable and I don't think his heart is pure in fighting back when he is hurt. He will not gamble."
The 27-year-old will sign a contract later this week to fight Lewis, which will guarantee him more than �1.25million while his opponent will pick up at least �6.25million.
"I have been preparing myself for this for the past six years. I'm not doing it for the money, I've had two fights worth more than one or two million dollars, I know I can beat him."
Grant added: "He is known for his big right hand and he has upper body strength. This fight will be about discipline and who is ready. I have both of these under control.
"I have to be consistent with my discipline and not get cocky. I hope to let the fight go and then deliver."
AFP