Although admitting he doesn't have any military experience apart from private use of a gun, the former World No. 31 told Sky News: "Of course, I would fight, it's the only reason I'm trying to get back. My dad and brother are surgeons, they are stressed out, but I speak to them frequently — they sleep in the basement."
But for the 21-year-old Yastremska, her family made the heartbreaking choice to ensure she and her sister were safe.
On Friday, Yastremska posted on Instagram that she was "in my home town and staying in with my family".
She added: "I haven't left home to do my favourite job. There's a war in Ukraine! I love you all and I genuinely believe that peace will be restored soon! Stay safe!"
But the following day, a series of pictures showed the tennis star and her 15-year-old sister Ivanna leaving her homeland.
"After spending two nights in the underground parking, my parents made a decision at any cost to send me and my little sister out of Ukraine! Mom, Dad, we love you very much, take care of yourself!!! I love you my country! Ukrainians take care of your lives," she posted.
She posted a series of pictures in the post, including an image of the pair looking upset and her sister crying while saying goodbye and videos of them waving to their parents on the shore.
ESPN reported the pair got on a boat 150 miles from their home in Odessa to the city of Izmail, having spoken to the tennis star when she had reached safety.
Fellow tennis stars commented on the posts.
"Praying for you and your parents! Sending love and strength," 2017 US Open champion Sloane Stephens wrote.
Amanda Anisimova, Victoria Azarenka, Yulia Putintseva, and fellow Ukrainian Marta Kostyuk all added heart emojis.
The sisters went through Romania but have ended up in France, ahead of the Lyon Open, where Yastremska will play.
Yastremska also posted in her Instagram stories, writing: "Tired, by my sister and I are safe! Thank you France. Ukraine, stay strong. We miss you home, mum and dad!"
She said she didn't want to draw attention to herself but more the effects war has.
She said she constantly messages and calls home to check on her parents who were safe but hiding in the parking garage but said it was an awful position to be in.
"I am so scared," she said told ESPN. "We don't need to kill each other like this.
"I am scared for my parents, my friends, and everybody in my country," she said. "For you to understand what a missile strike is like, you need to feel it. But, I wish (nobody) has to ever feel this (pain)."
Ukraine is well represented in the tennis world by nine women and three men ranking in the world's top 300 players.
The highest ranked player from Ukraine is World No. 15 Elina Svitolina, who told Sky News: "I'm shocked still in this terrible nightmare of what's happening in Ukraine. I'm really praying every single minute for my family for my friends for all people in Ukraine and around the world for safety, for peace.
"It's really stressful for me because I can not do anything. I can not go and help them. I wish I could help him. I can't even imagine what they are going through.
"It's something that's bigger than everything. It's war, it's the people and we have to stop it."
