The veteran coach believes that Italian teams' history against Germans means the Bavarians cannot afford to rest of their laurels on Wednesday
The Bavarians defeated Antonio Conte's men 2-0 at the Allianz Arena last week, but despite their advantage, the Republic of Ireland boss does not think die Roten are through to the semi-finals yet.
"The Germans are favourites, but only by 51 per cent," the 74-year-old told La Stampa on Monday.
"I'm optimistic, because history has shown us that we Italians often play great matches against German teams."
Trapattoni went on to say that while the German champions have stars like Arjen Robben, Franck Ribery and Bastian Schweinsteiger, other factors can also be important in the game.
"Bayern have the best Dutchman, the best Frenchman and the best German player. However, in football, there are different values that come into play," he concluded.
Juventus and Bayern kick off at 20:45CET on Wednesday.