While his advisor Shelly Finkel spoke confidently of a fight in the middle of the year, Tyson, 37, said he was old, tired and out of shape.
Finkel told Reuters that Tyson, who has not fought since knocking out Clifford Etienne in the first minute of their 10-round bout in February last year, could fight in June or July.
"We're looking at late June or early July," he said. "Mike has to start training again and get himself going.
"When he does (fight again), it will most probably be in the United States. It's too early to talk about an opponent."
But asked in an interview on Fox News Channel whether he thought he would fight again soon, a dispirited Tyson replied: "I don't think so."
"I'm old, I'm tired, I'm out of shape," he continued. "I don't know. It's probably too difficult to get into shape now ... I'm exhausted now."
Finkel, who said he hopes to "firm up" an agreement to officially manage Tyson, said the fighter was capable of more success.
"Physically he can do it and mentally he can do it if he wants to," he said. "He definitely has some more 'career' left in him.
"I don't think he has to prove anything. His last fight showed what he can do. He can do it if he wants to."
Tyson's career has been punctuated by run-ins with the law and outbursts of bad behaviour.
He served three years in prison for the 1991 rape of a former beauty queen and was suspended from boxing after he bit off part of Evander Holyfield's ear in a 1997 heavyweight title bout.
On Thursday, Tyson began 100 hours of community service, instructing youngsters at Gleason's gym in Brooklyn, after pleading guilty last month to charges of misdemeanour following a 2003 brawl with two men in a Brooklyn hotel.