The ex-German international spent two spells with die Roten where he won three Bundesliga titles and one Champions League.
However, the former skipper believes an "improved" La Vecchia Signora have the edge over his former employers.
“I don’t think they [Bayern] are favourites,” the 44-year-old told Ita Sport Press.
“That is because this Juventus side is different from the one that started the competition.
“They’ve improved so much since then, especially in terms of their self-belief,” added the former Fiorentina, Borussia Monchengladbach and Wolfsburg midfielder.
The German club will be confident of their chances having thumped Hamburg 9-2 at the weekend to maintain their 20-point lead over second-placed Borussia Dortmund, but Effenberg believes this will count for nothing against the Bianconeri.
“Should Bayern have an off day there is no real leader in their side who can drag the team along," he continued.
“That is a limitation because a successful side needs to have personality and a competitive nastiness.”
The two teams meet in Munich on April 2 before the return leg in Turin on April 10.