(NEW YORK) -- Ukrainian tennis star Sergiy Stakhovsky is known for representing his nation on the court, but now he's preparing to do the same on the battlefield.
"I just had this strong feeling that I have to do it," Stakhovsky said in an interview on ABC News Live on Thursday.
Stakhovsky was vacationing with his family in Dubai when Russia invaded Ukraine on Feb. 24. Almost immediately, he made the tough decision to say goodbye to his wife and children to defend their country. He's become a member of the army reservists, helping to protect Kyiv, the capital of Ukraine.
"I didn't really say goodbye to the kids. I just kissed them goodbye, and I said that I'll be right back. They were watching cartoons and reading books, not really paying attention," Stakhovsky said, explaining they were unaware of why their father was leaving their trip early.
Stakhovsky said leaving his wife was more difficult because as soon as the war started, she was able to tell he wanted to leave and fight.
"We didn't have an open discussion about it. But she had that feeling and I just didn't want to bring up the topic way too early, too, we were on vacation. Right now, it's something she understands and she accepted. And I hope I'll have a chance to ask for forgiveness in person," said Stakhovsky.
Leaving loved ones to fight for Ukraine is a scene thousands have been forced to face over the last eight days. While women and children fleeing the nation have been able to cross the border and find safety in neighboring countries, men ages 18 to 60 have had to pick up a weapon and fight.
Because Stakhovsky was on vacation and already outside the country, he could have stayed back with his family. But he said he thought of his brother, father and the other people fighting for freedom and made the decision to drive back home, into a war zone.
Stakhovsky said it was "one of the toughest decisions" he's made with no obvious right answer. He feels guilty for leaving his family, but, he said, "If I stayed I would have felt guilt that I left my father and brother in Ukraine."
"Crossing the border was a tough choice because I knew that's the point where, you know, you don't go back," he said. "But by driving through Ukraine, driving through the country, seeing all the people coming into groups, doing their own resistance units with hunting guns, barricading the roads, it's really inspirational."
Stakhovsky retired from professional tennis at the Australian Open in January. He won four career singles titles and four doubles titles and had a career-high singles ranking of No. 31 in the world in 2010. Now, he's learning to use military weapons to protect a nation under attack.
"I feel I am not prepared enough, that's for sure. But I guess no one is prepared enough," Stakhovsky said, talking on Zoom while hunkering down with fellow soldiers in Kyiv.
He said having Ukrainian President Volodymyr Zeleskyy "willing to go the distance and willing to risk his life staying in the capital while being surrounded by troops of Russia" is helping push him and the other reservationists forward.
He believes his troop is the last to join the reserves and they hope they don't have to fight, but if the moment comes, he said he's ready to do whatever it takes to help protect the freedom of Ukrainians.