The Chile international sustained a thigh injury in Juventus' 4-2 Serie A loss against Fiorentina on Sunday and the Italian champions fear that the combative midfielder might not recover in time for Wednesday's encounter at the Santiago Bernabeu.
Vidal started the match against Fiorentina from the bench for disciplinary reasons after returning late from international duty with Chile, but was brought on for Claudio Marchisio late in the second half.
Although the midfielder lasted until the final whistle, he complained about pain in his thigh afterwards and he could consequently miss the game versus Madrid.
Juventus desperately need a good result against Real Madrid after dropping points against Copenhagen and Galatasaray in their opening two Group B games.
