The Croatian midfielder played with Bale - who recently rejoined former club Tottenham on loan for the current campaign - in Spain for seven years and dismissed the idea that the Welshman had struggled to get to grips with the language, claiming that he was just "shy".
Modric told COPE: "I have been with Gareth most of my professional life and he is a spectacular guy. He is shy, similar to me.
"What is said about him is not fair, they judge him in recent years but what he has done at Madrid is something impressive and he will always be remembered as a player who has done a lot for the club.
"He has never had any problems in the dressing room, he is a great guy. He spoke Spanish, he joked with us."
He continued: "In recent years many things have come out and they have forgotten what he has done. When time passes they will remember him and how important he has been.
"Every person has their own behaviour. He was like that, he didn't associate much, but in the dressing room he was very good. It makes me sad that everything he has done has been forgotten in the last year."
Modric also backed Eden Hazard to come good after struggling with injuries since his high profile move from Chelsea.
He said of the Belgian: "It is not a comfortable situation for him. He has come to show that he is one of the best players in the world and I am sure he will prove it this year."