Cristiano Ronaldo picks Lionel Messi to win Ballon d'Or in January

Cristiano Ronaldo says the 2014-15 campaign was "probably the best season of my career," but he still predicted that Lionel Messi will win the Ballon d'Or for the fifth time in January.

The Real Madrid star is a candidate to win his fourth at the ceremony in Zurich, but he said that Messi has the advantage this year after the Argentine led Barcelona to the Treble last season.

"To be honest, I think Messi is going to win this year because this kind of trophy, it depends on votes," he said on "The Jonathan Ross Show," set to air on Saturday night.

"You win competitions, you win the Champions League, you win the league in terms of individual. I did probably the best season of my career, which is good and I was the highest scorer in Europe, [but] it's all about votes, it's difficult, and to be honest, I'm not very worried about that because as I said many times, I never thought I'd win three times, to be honest."

Although the award has gone to either Ronaldo or Messi in each of the past seven years, Ronaldo declined to call Messi his "rival."

"I don't have rivals, we have a normal relationship," Ronaldo said. "We shared this stage at FIFA for eight years. No one has done that in the past -- only us -- so it's good.

"I have a good relationship with him, he plays for one club, I play for another club. He won the best for him, I won the best for me.

"We have a good relationship, we are not home friends, but we respect each other."

During the lighthearted interview, Ronaldo also said he still cannot understand what his former manager Sir Alex Ferguson is saying.

The Real Madrid forward described Ferguson as a "father'' figure who was vital in shaping his career during six years at Manchester United, but told Ross that he still finds the Scottish manager's Glaswegian accent impenetrable.

"I still don't understand him. In the beginning, I had a translator, a Brazilian man, of course, basically only for him,'' Ronaldo said.

Ronaldo, who is the subject of a documentary about his life that is now on general release, spoke of his affection for his time in England.

"I respect English people a lot because they are very polite and they respect [you],'' he added. "But it's true, the time I spent here, people treated me unbelievably. I'm never going to forget that.''

Ross also asked Ronaldo about a number of the issues that were touched on in the documentary -- his relationship with his father and his mother, and how he will never publicly reveal the name of his son Cristiano's biological mother.

Ronaldo said he had never forgotten Ferguson's compassion in allowing him to visit his late father -- who suffered from alcoholism -- when he was ill.

"I just have to say thank you for what [Ferguson] did for me,'' he said. "We had an important game in the Champions League, and I said, 'Coach, I need to go to see my daddy' and I was a key player, I was a very important player, and he said, 'Listen, your personal life, your family is the important thing that you have in your life. If you want to go three days, four days, five days, you can go.'

"This moment is what I keep for me because it was the most important time in my life and he shared it with me. This is why I respect him, and for me, he's the best coach I ever had.''

Ronaldo also revealed that he barred his mother from watching big games because she gets too nervous watching him play.

"I just make a rule, big games she cannot watch,'' he said.

"It's true, I don't take her to my box, or I put someone in the home to go and walk with her when the game starts. It's the solution. ... I understand my family cannot deal [with it] because it's difficult when press start to speak on television all the time ...''

Despite his devotion to his mother, Ronaldo does not believe it is a problem that the mother of his own child -- also called Cristiano -- will play no part in his life, but says he will tell his 5-year-old son who his mother is.

"For me, it is not a problem,'' he said when Ross asked him what he would say to his son. "I will say, in the world, many kids don't have mums, don't have dads or dads die or mums die. ... Cristiano has a dad, an unbelievable dad. [He has] a grandmother, I have the support of my family, great of course."