Milan - Italy midfielder Claudio Marchisio was carried off on a stretcher during a Serie A clash with Palermo on Sunday, prompting fears less than two months before the start of Euro 2016.
Marchisio, a key player for Antonio Conte's Azzurri squad, appeared to hurt his knee when he fell under a challenge less than a quarter-hour into the game.
He is expected to undergo scans later Sunday or Monday.
A win for Juventus on Sunday will take the Scudetto holders' Serie A lead over Napoli to nine points with five games remaining this season.
Juventus is aiming for a fifth consecutive league title, a feat they last achieved in 1935.