David Haye has admitted that he is staying in shape in case a fight with one of the Klitschko brothers is agreed.
The former WBA heavyweight champion retired in October following a defeat to Wladimir Klitschko but his camp is still in talks over a potential bout with the Ukranian's brother Vitali.
Haye told BBC Sport: "My people are talking loosely with Vitali's people and they have shown a keen interest in a potential fight.
"I'm going to stay in shape if that call comes, and if it does come I will be heavyweight champion again."
Vitali is currently preparing for a title fight against Dereck Chisora, planned for March.
