Carlo Ancelotti said Real Madrid's reserve goalkeeper Andriy Lunin missed the 1-0 win at Rayo Vallecano with an elbow injury, but revealed he has understandably been affected by Russia's invasion of his home country of Ukraine.
Lunin, who is second choice to Thibaut Courtois, dropped out of the squad on Friday.
Russia invaded Ukraine on Thursday, following weeks of rising political tensions in the region.
Several high-profile sports figures have publicly expressed their opposition to the war, including Russia's Andrey Rublev who wrote "no war please" on a camera lens at the Dubai Tennis Championships, joining compatriot Daniil Medvedev in calling for peace.
In the Premier League, Manchester City and Everton showed solidarity with Ukraine ahead of their meeting at Goodison Park on Saturday.
City's Oleksandr Zinchenko and Everton's Vitaliy Mykolenko embraced during the warm-ups, the two Ukrainian players receiving a warm reception from fans inside the ground, with each appearing close to tears as more tributes were paid before kick-off.
Lunin was not present at Vallecas to receive any such support, with Ancelotti saying after the game: "He had a swelling in his elbow, he couldn't move it this morning.
"It is a medical problem, but I cannot hide that the player is affected. He is thinking about what is happening there, he has people close to him in Kiev."
Madrid left it late to secure all three points against their neighbours, Karim Benzema's 83rd-minute goal sealing victory.
Asked about the game, Ancelotti said in quotes reported by AS: "Satisfied with the work, with the commitment, we knew that it was going to be competitive in all facets.
"We risked it on the counter-attacks, we tried to combine up front and win the match.
"We did, although I'm not very, very satisfied. It was a difficult place to play, because of the atmosphere, the rivals, the grass that was not good... Nobody wins here by a large score."