Vitali Klitschko (left) met Haye at London's O2 Arena in November
WBC heavyweight champion Vitali Klitschko has declared his interest in fighting Britain's David Haye.
Haye has already seen one bout with Vitali, 37, fall through and was due to face the Ukrainian's brother, IBF and WBO champion Wladimir, on 20 June.
An injury to Haye saw that fight scrapped, but Vitali remains an option.
"Let's talk in the ring with the fists," Vitali told BBC World Service. "He is injured, he has a big mouth but this fight will be very interesting."
Haye's manager revealed recently his boxer wanted to fight Vitali and September looks a possible date.
Haye, the former undisputed cruiserweight king, picked up a back injury while training to meet Wladimir and returned to the UK to have intensive physiotherapy.
The 28-year-old Briton insisted at the time he would be ready to fight on 11 July, three weeks after the original date, but the Ukranian's camp were unwilling to wait.
Wladimir instead met the joint WBA champion Ruslan Chagaev in Germany, defeating the previously unbeaten Uzbekistan-born fighter with a 10th-round technical knockout.
Following that fight Wladimir said that he would now target joint WBA champion Nikolai Valuev, leaving Vitali as Haye's most likely option.
Manager Adam Booth said two weeks ago that Haye was keen on a clash in September, adding that if "Vitali wants to fight he would be up for it".
Despite Haye recently bad-mouthing both Klitschko brothers, Vitali said he was very interested in the fight.
"I want to see him in the ring," he added. "I don't fight for myself - not for me - I fight for boxing.
"We are discussing the details right now about the time and I think in September it can happen."
Vitali has only lost two fights, first when he was forced to retire with a shoulder injury against Chris Byrd in 2000 and the second when he was stopped on cuts by Lennox Lewis in 2003.
He was ringside to watch Haye's five-round demolition of Monte Barrett in London last November and a fight was set only for Vitali to pull out in order to make a mandatory defence of his WBC belt.
Haye is hoping to become Britain's first heavyweight world champion since Lewis retired in 2003.