Joselu left Real Madrid last summer for Al-Gharafa and remains close to his former teammates, including Carvajal.
He recalled to Jugones: "I experienced it very badly when I saw Dani's (Carvajal) injury, because I know what it is like. I get emotional thinking about it. I can't get it out of my head. I wrote on social media that 'I would have preferred it to have happened to me'.
"I picked up the phone and called the physiotherapists, the doctors...
"My wife and I were devastated. He called me in the ambulance and told me that they had told him it was over (his career)."
The veteran also said: "Dani will come back as before and even better. I know how stubborn he is. He wants to play the Club World Cup. People told him not to set goals, that it would be worse if he didn't succeed, but he doesn't care. He's stubborn and he won't respect anything."