Porto are "extremely united" behind Iker Casillas following his heart attack, the team's head coach Sergio Conceicao has said.
It was later confirmed that the 37-year-old had suffered a myocardial infarction, though he is in a stable condition and on course to make a recovery.
At a news conference ahead of their game with Desportivo Aves, Conceicao spoke of his players' shock when they were informed of the seriousness of Casillas' problem.
"When it happened I must say we didn't think it was very serious, we thought it was just some indisposition like sometimes happens," Conceicao said.
"But after 15, 20 minutes of training we were not so focused because of that situation and in the end we had the news, the doctor called me and that was when I felt the team was shocked with what happened.
Todo controlado por aquí, un susto grande pero con las fuerzas intactas. Muchísimas gracias a todos por los mensajes y el cariño pic.twitter.com/i3TXsELUGD— Iker Casillas (@IkerCasillas) May 1, 2019
"In that moment we were apprehensive then we had knowledge of the seriousness of the situation, but fortunately Iker is well and the team is with him and extremely united for him and for his family because football is part of life, but life itself is much more important than anything else.
"The team obviously feels the same way when a health problem or something similar happens to someone in the team, the team is very united and they felt it like it was happening to them."
Quentin Beunardeau, who plays for Porto's next opponents CD Aves, told Goal: "I was sad for him. He is a football icon. A great goalkeeper. He was my idol when I was younger. I would have liked to play a third game against him, but he is alive and that is the most important thing for him and his family.
"Here, all the newspapers talk about it. It's something serious. It was a shock for everyone."