The Juventus star won the Ballon d'Or at United under Ferguson.
However, Vidic has revealed that there was a time when Ronaldo and Ferguson didn't have a perfect relationship.
“I think Ronaldo wasn't happy when he [Sir Alex] shouted at him," Vidic told the League of Legends podcast.
“In the beginning it was one time he said something to Ronaldo, but he accepted it very emotionally
“He took it personally, but he was very young - he was 20-years-old."
He continued: “Of course you realise, even me, that next time you will not tell him [if he does something wrong].
“It's better to not tell him because otherwise he will be too emotional and he won't help you be better."