The Bianconeri laboured to draws against Copenhagen and Galatasaray in their opening two fixtures, meaning they already sit four points behind Carlo Ancelotti's men in Group B.
Juve midfielder Paul Pogba claimed this week that his side will win at least one of their two clashes with the Spanish giants, and Platini is also of the opinion that anything is possible in this season's tournament.
"I agree with him [Pogba]. Football has levelled off, especially in the Champions League - everyone can beat everyone else, and anyone can lose against anyone. Chelsea, for example, lost in London to Basel," he told Tuttosport.
When asked if Juventus could go all the way in this season's Champions League, he added: "Why not? Last season, returning after a year of 'purification' without Europe, they reached the quarter-finals. If the draw is not particularly malignant ..."
The Serie A champions currently find themselves two points behind pace-setters Roma, who have won all seven of their opening league games under new boss Rudi Garcia.
Although the form of the Giallorossi so far this season has taken many by surprise, Platini insists he was never in any doubt as to the abilities of his compatriot following his achievements in Ligue 1.
"The Italians underestimated him. In France, we knew how good he was," said Platini. "He showed that immediately. After all, you can't win a title with Lille if you're not of that calibre.
"We're only at the beginning of October, and Juve are still there. Of course, with a fit [Francesco] Totti, Roma can reach any goal.
