The Italian believes the signings of Carlos Tevez and Fernando Llorente has added an extra dynamic to the side and feels Real Madrid will have to be at their best to beat them
The Spanish champions host the Serie A holders on Wednesday with four points separating the sides after just two rounds of matches, but Ancelotti insists they will face a stern test to record a win at Santiago Bernabeu.
"Juventus are very motivated and very well organised, with quality players," the 54-year-old was quoted as saying on the official Uefa website.
"They've signed some important players in the summer, like [Fernando] Llorente and [Carlos] Tevez who have given the team some extra quality.
"They have played together for three years under the same coach and it's a well-structured club. Those are their biggest qualities."
Juventus have collected two points from their opening two Group B games with Copenhagen and Galatasaray, while Madrid have recorded wins in each of their first two games.