Ferguson kicked off hostilities ahead of United's trip to Stamford Bridge by criticising the Football Association's decision to rescind the red card John Terry received against Manchester City last week.
The controversial call means the Chelsea skipper will be available on Sunday, and Ferguson accused the FA of playing favourites.
The United boss's fury has been further stoked by the absence of Nemanja Vidic - suspended after seeing red against Liverpool - although, on the upside, Ronaldo looks set to make his first start of the season.
Scolari had been happy to sit back in silence while Fergie did his thing, but now the Brazilian has fuelled the flames by admitting he has designs on the Red Devils' Portuguese superstar.
Father & Son
“Maybe next season, Cristiano is with me. Tell him if he wants to change, I’ll open the door for him,” he said in The Sun.
It would not be the hugest surprise if Scolari attempted to lure Ronaldo to London, as the pair are famously close from their time with the Portugal national team.
The United winger would also link up with fellow Seleccao Jose Bosingwa, Paulo Ferreira and Deco at Chelsea, and he has shown he is open to more lucrative deals away from Old Trafford.
Scolari continued: “He will leave United one day because he won’t play for 50 years.
“If he goes to another club, whether in one year or two years, I don’t know. He’s my friend. I like him as a father likes his son. But his life is his life.”
The likelihood of United allowing Ronaldo to join the Blues is very remote, however, as evidenced by Ferguson's refusal to let the 23-year-old make his dream move to Real Madrid during the summer.
The North-West giants very rarely sell their stars before they reach the peaks of their careers, meaning they will be loath to offload a player whom Scolari believes is among the very best on the planet.
“Now, at this time of life, Ronaldo is mature and is better than one or two years ago,” the former Brazil boss added.
“Now he is one of the three best players in the world. I said that two years ago, and I repeat it now. I never said he was the best, and I won’t now.
“I have some players here who are fantastic, and I’d never say they are the best. He is one of three, one of five, one of 10.”