Allegri returned to take over at the helm from Andrea Pirlo this summer, and was told Ronaldo would stay at the club, despite constant speculation over his future. According to Il Giornale (via the Daily Mail), the Italian is furious with club president Andrea Agnelli and sporting director Federico Cherubini.
The report also claims that the Juve boss told the club's chiefs that "these were not the agreements" when he agreed to come back to the club. The Serie A giants brought in Moise Keane from Everton on deadline day to fill the gap left by Ronaldo's departure and also signed Manuel Locatelli from Sassuolo earlier this summer.
Following their shock 1-0 home defeat to Empoli over the weekend, Allegri told DAZN: "Cristiano spent three years at Juventus, he scored goals, which he is very good at, he's an extraordinary player, but we cannot think about Ronaldo from now on.
"I have a fine squad, we simply must realise that we can't just dominate every match. We need to come together and this will help us for the future. I am optimistic, always."