Ukraine's Vasily Lomachenko has turned down the chance to regain the lightweight world titles against Australian George Kambosos Jr.
Instead, the former boxing world champion will remain in his home country to fight against the Russian invasion and assist in the war effort.
Lomachenko would have been required to leave Ukraine in the coming days to begin his training camp under the terms of the contract.
The fight was set to take place on June 5 at Marvel Stadium in Melbourne, in what would have been one of the biggest prize fights in modern-day boxing.
However, Lomachenko's manager Egis Klimas reached out to his opponent's camp last night to inform them that the Ukrainian would no longer be taking the fight, despite being given the green light by the Ukrainian government to leave while the country is under martial law.
Kambos Jr. responded in a Tweet, saying: "I respect your decision and I totally understand and I pray for you and your country.
"Please stay safe and once I wipe the floor with Devin, we will make this fight between two real champions. God bless."
As mentioned in the tweet, American boxer and WBC Lightweight Champion Denis Haney has been offered to replace Lomachenko in Melbourne, but the contract is yet to be signed.
Kambos tweeted at Haney: "You were offered [the fight] months ago & you played around.
"In the meantime the great man Vasiliy Lomachenko made it very simple to do anything to make it happen & it was a done deal. But Loma now has a bigger fight [at the moment] which I totally respect so let's see how much of your word is true."
Lomachenko is reportedly stationed right in harm's way, according to the Ukrainian's promoter Bob Arum.
He told Fight Freaks Unite: "The Russians are firing rockets from ships at Odessa. It's a major port.
"From the standpoint of what he did it was very courageous and I can understand completely why he did it.
"From the standpoint of pure boxing I'm disappointed because it was an opportunity to win back all the titles and it was gonna be a massive fight, and it's not gonna happen.
"But certainly I sympathise completely with Lomachenko. I understand what his position is.
"It was a very courageous position and I blame only one person for this whole travesty and that's Putin."
Haney is expected to sign on the dotted light after responding to Kambosos posting the flight time from Las Vegas to Melbourne.
Haney responded: "I know how long the flight is... long as my d**k! Don't try to talk me out of it b***h I'm on my way!"
Featured Image Credit: Joel Plummer/ZUMA Wire/Alamy Live News. Facebook/Vasiliy Lomachenko