AC Milan right-back Ignazio Abate limped off the San Siro pitch in the 17th minute against Palermo on Saturday with an apparent leg injury.
The problem is muscular, according to the official Serie A Twitter account, but it has not yet been confirmed.
Abate grimaced as he was substituted by Davide Calabria, the 18-year-old youth product who in turn made his second Serie A appearance.