Milan will be without Ignazio Abate for at least two weeks after the defender was diagnosed with a right thigh muscle injury, the Serie A side said.
Abate lined up for Milan’s Champions League match at home to Malaga on Tuesday but was replaced after six minutes.
Milan went on to draw the match 1-1, a result which sent Malaga through to the last 16 knockout phase and left the hosts second in Group C, a point above Anderlecht with Zenit St Petersburg two points further adrift.
Milan said Abate would be sidelined “for at least 15 days” after which time the club would “undergo further checks”.