The Paris Saint-Germain star won the world’s best player award for a record seventh time on Monday, with CR7 not even attending the ceremony.
Allegri worked with Ronaldo at Juventus in the 2018-19 season, with the striker top-scorer as they won Serie A.
The pair were reuinited in the summer when the Tuscan tactician returned to Turin, but the five-time Ballon d’Or soon left for Manchester United.
His battles with Messi has defined an era of football, and despite personal experience of working with the Portuguese, Allegri named his rival as the world’s best.
Asked about the award in his press conference following the win over Salernitana the Juventus boss replied: “In the Ballon d’Or they voted for Messi, let’s say on a technical level Messi is the best in the world.
“After that I don’t know how they judge the Ballon d’Or.”
It’s not the first time Allegri has shown a rather cool attitude toward CR7.
The Portuguese started on the bench for the first Serie A game of the season and, following his move to Manchester United, the 54-year-old didn’t seem bereft.
Allegri said at the time: “I’m absolutely not disappointed, because Cristiano made his choice and these things happen in life.
“Sivori, Platini, Del Piero, Zidane, Buffon – great champions – have passed through Juventus as well as many coaches. That’s how life goes.
“Juventus remains, which is the most important thing.
“In these three years he gave his contribution to Juventus and now life goes on.”