The Italian boss was quizzed about the 36-year-old's future in Turin, with Ronaldo heavily linked with a sensational move to the Etihad Stadium as he seeks a new challenge in the twilight of his career.
The Portugal international did not train with his current side despite being spotted at Juventus' training ground on Friday morning, after clearing his locker on Thursday evening.
It has been reported recently that the Portugal captain spent around 40 minutes at the training center on Friday after bidding farewell to his teammates, as he awaits his agent Jorge Mendes to bring an official offer from City in these next hours after expressing his desire to leave Juventus.
Previewing his side's Serie A tie against Empoli on Saturday, Allegri said: "I’m not disappointed by Cristiano Ronaldo. He wants to leave Juventus and he made a choice, he’s gonna look for a new club after three years here. It’s part of the life.
"Cristiano Ronaldo told me yesterday that he wants to leave Juventus immediately. It’s true and confirmed. This is why he wasn’t training today and he’s not available for tomorrow match versus Empoli.
"Things change, it's a law of life. Juventus remains, which is the most important thing. Cristiano (Ronaldo) gave his contribution, he made himself available, now he leaves and life goes on.
"Cristiano (Ronaldo) is to be thanked for what he has done, also as an example amongst the youngsters. But, as I said, we must go on."
It was reported on Friday that Ronaldo is nearing a move to the Etihad Stadium, with just a transfer fee to be agreed upon by City and Juventus, as it has been said that the deal could even be completed for less than £25 million.
After a flurry of quick events in recent days, Ronaldo is ready to fly to England in these next hours and seal a move to City, who are prepared to submit an official offer to Juventus for the ex-Manchester United talisman.
City are working to sanction the sales of a few key stars before proceeding with their pursuit of Ronaldo, who is entering the final year of his contract in Turin.
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