After last season's Champions League final between Real Madrid and Liverpool, Loris Karius grabbed the headlines for the wrong reasons after two of his errors led directly to goals.
The German goalkeeper has spoken to the Bild newspaper about those mistakes and also his clash with Sergio Ramos.
"Nobody will ever know the link between the blow I received and the mistakes I later made on the pitch. It's not an excuse, just an explanation," the Besiktas player said.
"I don't know if Sergio Ramos deliberately injured me. Only he knows, but it's not important.
"However, he has never said sorry to me. The tests that they did on me showed I had a visual impairment.
"In normal circumstances it's hard to imagine that I would make those mistakes."