Tyson Fury's manager and promoter Mick Hennessy is unsure Wladimir Klitschko will invoke his rematch clause with the newly crowned world heavyweight champion.
Unbeaten Briton Fury shocked the planet by capturing Klitschko's WBA, IBF and WBO belts with a unanimous (115-112, 115-112 and 116-111) points decision in Dusseldorf, Germany on Saturday.
It brought an end to Klitschko's nine-and-half year reign in his 19th title defence and was his first loss in 11 years. The former champion tweeted on Monday: "I still don't believe I actually lost. Man, I'm suffering."
A rematch clause in the contract means Klitschko is assured of an immediate chance to win back the belts next year, but Hennessy is uncertain the 39-year-old Ukrainian will box again after being outfoxed by his 27-year-old opponent.
"I've had no contact with them [Klitschko's team] since the fight but they've got a window to decide whether they want to step up or down," Hennessy told ESPN.
"I think Wladimir is really in two minds about the rematch because he looked really busted up to me at the press conference after.
I still don't believe I actually lost. Man, I'm suffering.— Klitschko (@Klitschko) November 30, 2015
"He couldn't get past Tyson's jab, couldn't cope with his movement and he's never experienced that before. He was hesitant about trying to let go, pulling the trigger.
"There's more to come from Tyson, he will get better because he's young, and that's what's worrying Wladimir.
"If the rematch does happen it will be May or June, not before, and it will happen where ever it makes commercial sense to happen. If it makes more money at Old Trafford or Wembley, then great, but where ever it is, even back in Germany, Tyson will knock him out in the rematch."
Hennessy dismissed Londoner David Haye's calls for a fight and says Fury is more likely to face 2012 Olympic gold medallist Anthony Joshua in the future.
Haye, 35, lost the WBA version of the world heavyweight title on a wide points decision to Klitschko in 2011 but last week announced he will return in January after a three-and-a-half year absence.
Haye twice pulled out of fighting Fury in 2013 due to injuries sustained in training and Hennessy does not envisage the pair ever fighting.
"It's publicity-hungry from Haye calling Tyson out, and disgraceful," Hennessy said.
"It would be a one round job for Tyson -- but we won't even go there. We didn't believe his two pull-outs and they stalled Tyson's career and have ruined Haye's reputation."
He added: "He's not in the same class as Tyson, he's fourth division."
Fury insists becoming world champion will not change his life, but it will bring fame as well as riches for the Lancaster-based traveller.
Fury is lined up to go on the The Jonathan Ross Show -- due to be screened to millions on UK channel ITV on Boxing Day -- and his unconventional, unpredictable and uncompromising personality is in stark contrast to that of Klitschko.
"People need to know how proper Tyson is and how genuine he is, and they will because there are a lot of things being lined up for him now," Hennessy said. "He's not chosen the easy route or the money route in boxing. But he chose to be proper, legit, every step of the way.
"But I also got involved with Tyson because he was a proper individual and restored my faith in the sport because I hated so much about it at the time.
"To bring someone through, every step of the journey, was a personal dream of mine, to take someone from the amateurs to the pinnacle of the professional sport.
"The ultimate goal of a promoter and manager in boxing is to lead a boxer from the amateurs to the world heavyweight title."