The Ukranian is dealing with the horrors being inflicted on his country by the Russian army, while playing for the Hammers in the Premier League and Europa League.
The 32-year-old did get compassionate leave in the early stages of the war, but has been in good form in matches since.
"David Moyes told me I could choose to train or not and that I had to do everything I could to ensure the safety of my family," Yarmolenko told Ukrainian YouTube channel Football 1/2/3.
"I needed to remain professional so I returned. I was just going crazy and you need to be distracted. But even now, I don't know what the other results are. It is just training ends and then the phone calls home.
"It is honestly scary to talk about it. We have to help each other. If we do not then no one will.
"I am sure we will not be beaten by any country. No one will ever be able to break our spirit."
He added: "When it all started, on February 24, I arrived at training and couldn't even talk.
"I had tears flowing. I asked the coach to let me go home.
"I didn't believe this could happen. I sent my family to Kyiv because my child had to have a doctor's appointment.
"Can you imagine what I was like when it started the next morning? I just wanted to run and hit my head against a wall. What a fool I was sending my family to Kyiv and I am sitting in London."