Juventus and Portugal superstar Cristiano Ronaldo opened up on the sadness he feels that his alcoholic father never saw his greatest football achievements.

Ronaldo, 34, has enjoyed a glittering trophy-laden career with club and country, while he is the recipient of five Ballon d'Or awards.

However, his father Dinis Aveiro passed away when Ronaldo was aged 20 after liver failure from excessive drinking and did not see Real Madrid's all-time leading scorer reach the zenith of his career.

"My family see, my mum, my brothers, even my old son, but my father, he didn't see nothing, and it was - he died young," Ronaldo said in an interview on ITV with Piers Morgan.

"I have to have these images to show my family. But I really don't know my father 100 per cent.

"He was a drunk person. I never spoke with him, like a normal conversation. It was hard.

"Sadness? To be the number one, and he don't see nothing, and he don't see me receive awards."

Ronaldo – a five-time Champions League winner – also admitted he has banned his mother from attending big matches for her own health.

Maria Dolores dos Santos Aveiro, 64, has collapsed on a few occasions at tense games which prompted the Juve forward to step in.

"She gets so nervous, I don't understand. She is not allowed now to watch big games," he added.

"I get friends to stay with her and she goes for walks around the house. She fainted two times in the stadium. She is nervous.

"It is impossible, I don't have a father anymore and I don't want to lose my mum, so I told her 'you will not watch semi-finals or finals anymore'."