Thibaut Courtois says Eden Hazard still wants to be a success at Real Madrid and cannot be written off as a failure.
Hazard has not started a game since Madrid suffered a shock defeat at home to Sheriff in September, an opponent they play again in the Champions League on Wednesday.
Madrid coach Carlo Ancelotti has praised Hazard's professionalism but admitted last month that he currently "prefers other players".
The Belgian has been linked with leaving the club either in January or next summer, having endured a nightmare two years since joining Real Madrid from Chelsea for €100 million.
"I have known Eden for many years and his dream has always been to play for Real Madrid so he feels sad that it's not going how he wants it to," said Courtois in a press conference.
"I do not see him as someone with his head down, I see him training to the maximum because he wants to be successful.
"He will play when the boss puts him on but I am sure that his day will come, because we cannot forget the quality that Eden has. These days we forget very quickly the talent of the players, this quality and this talent does not go away.
"We cannot forget him or kill him or think that he is just any player, because he is not."
Real Madrid are top of the group, two points clear of Inter Milan and three ahead of Sheriff. Madrid face Inter Milan at home in the last group match.
"We know Sheriff well and they know us well, we have to play a complete game," said Ancelotti.