The Ukrainian tennis star who left his wife and children behind to fight Russia spoke of life on the frontline today.
Sergei Stakhovsky, 36, best known for his defeat of Roger Federer on Wimbledon's centre court in 2013, has joined his country's reserve forces.
Boxers Vasiliy Lomachenko and Oleksandr Usyk have also signed up to fight for their country.
Sergei retired from tennis following the Australian Open in January and now finds himself in Kyiv preparing for war.
"It is horrible leaving my wife and children behind," he said. "My kids do not understand war. They think I am at a tournament."
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It is 'extremely hard' on his wife Anfisa. There will be no military training but he told the BBC : "I know how to use a gun.
"If I'll have to, I'll have to." He admitted the level of fear rose as he crossed the border into Ukraine and he knew there was 'no way back'.
"But then you see the people and the level of cooperation," he said.
"They are putting down obstacles for the Russians, they work non-stop to beat the fear. I guess that is the best way of doing it."
Hundreds of tennis players have sent messages of support, praising him for his courage.
He backed the worldwide sports ban on Russia, adding: "When a Ukrainian steps on the court to play a Russian, he sees the flag of a country which every single Russian troop is flying while killing civilians and shelling civilian cities.
"I think that is unimaginable." His father and brother, both surgeons, are 'sleeping in the basement'.
Reigning heavyweight champion Usyk, who beat Britain's Anthony Joshua in September, has left his London base to go to Ukraine.
Instagram photos show the 35-year-old holding a weapon. Lomachenko, 34, is seen wearing a military uniform with a rifle across his shoulder on his Facebook page.
Men aged 18 to 60 have been told by the Ukrainian government to stay and fight as it looks to slow Russia's attacks.
Britain's Tyson Fury was quick to praise Oleksandr Usyk for signing up.
Speaking at a press conference before his fight against Dillian Whyte, Fury said: "I would be on the front line if England or the US got involved.
"So would my dad and all the boys (the Fury brothers). Love your woman and defend your country."
Fury first became world champion in 2015 after beating Ukraine's Wladimir Klitschko, who is also believed to have signed up.