Pep Guardiola described Oleksandr Zinchenko as "an incredibly strong guy" for his attitude amid the escalating crisis in his home country of Ukraine.
Zinchenko joined a group in Manchester demonstrating against Russia's invasion of Ukraine outside the city's Central Library on Thursday.
The full-back had previously expressed support on Instagram for his compatriots at home and condemned the actions of Russian president Vladimir Putin, who ordered the military action on Thursday.
Manchester City boss Guardiola would have no problem selecting Zinchenko for Saturday's Premier League game at Everton.
"We spoke personally with him and everyone has spoken," Guardiola said. "These are headlines today all around the world, and it's a concern but Aleks is an incredibly strong guy.
"It's not easy, but yesterday in training, he was brilliant. He is ready to play if he has to."
When asked about Zinchenko attending the Manchester vigil, Guardiola said: "What would you do if someone abroad attacked the UK?
"It's how he feels. What happened in Yugoslavia, no-one did anything. Around the world, there are many wars. It's a pity. Innocent people will die when they just want to live in peace.
"All around the world, you want a house, to sleep well, food on the table, movies, food, someone to love. When you are not involved, they attack your country, and it should be complicated to arrive at this point.
"Always innocent people pay the terrible price, the decisions of one or two people; still we don't learn what happened in the past. Right now in Syria, many places. At the end, the strong part always kills the weak one."
City saw their 15-game unbeaten run in the league end in a dramatic 3-2 home defeat to Tottenham last time out, Harry Kane scoring an injury-time winner moments after Riyad Mahrez had made it 2-2 with a penalty.
Liverpool's 6-0 thrashing of Leeds United in their game in hand means City now lead the Reds at the top of the table by just three points with 12 matches remaining.
"When we were champions, it wasn't in December or January," Guardiola said. "[On Thursday] We saw Wolves-Arsenal, so intense, they are so good. What's next? Try to win the next game.
"Why should I not be excited? I'm more than delighted to be in this position. We want to defend it, attack better and try to win games. It's so tough, I saw yesterday the game, how Tottenham played the last game. Every game is so difficult.
"What we achieved in the last years, the contenders are so intense. From the start of the season, I couldn't expect it wouldn't be what it is now.
"I'm more than grateful we're better than I thought at the start of the season. The way we defend some situations, we didn't deserve to win, trying to attack when defending teams in this way.
"A football teams never ends, is never finished. Every time we can go to training to do better. Otherwise, it would be so boring. I never felt it would be over. We want to be there and this is what I want from my team."