Arsenal manager Arsene Wenger has revealed that defender Laurent Koscielny was 'deeply affected' by last week's terrorist attacks in Paris.
Suicide bombers killed 129 people after striking six different locations, including the Stade de France, in the French capital on Friday night.
Koscielny and Arsenal teammate Olivier Giroud were playing for France against Germany when three bombers blew themselves up outside of the stadium.
The defender took part in Tuesday's international friendly against England at Wembley, where both nations stood in solidarity, but Wenger noticed that his player was still carrying the pain of the atrocities.
"He had a fantastic game against Germany," Wenger told reporters in today's press conference. "You could see that on Tuesday night he was not himself.
"It affected him deeply and I didn't recognise the player I saw on Friday night on Tuesday night. I will talk with him. What I will want from him is that he's completely committed and feels ready. If not, I will not play him.
"You have to trust the player in these kinds of situations. Sometimes it hits you more two or three days later than on the night. On the night you try and protect yourself or not know what's going on. But slowly you realise the shock is always a bit after. They have gone through that game but I will talk to them to see how much they are up for it."
Arsenal will play West Bromwich Albion at The Hawthorns this weekend.