AC Milan defender Alessio Romagnoli has joined the club's lengthy injury list after the Rossoneri confirmed that its captain has a calf injury.

Romagnoli sustained the injury during training on international duty on Friday and reports in Italy suggest he could be out for a month.

Milan said examinations conducted by the club's medical staff diagnosed Romagnoli with "a lesion of the myotendinous junction of the medial segment of the left calf".

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Romagnoli has been a key player in Milan's recent rise up the Serie A table, scoring late winners in consecutive matches against Genoa and Udinese.

His injury is another blow to coach Gennaro Gattuso, who is already without a raft of players including Lucas Biglia, Giacomo Bonaventura, Mattia Caldara and Mateo Musacchio.

However, Ivan Strinic could soon be available after the Croatia defender was cleared to resume training following a heart problem.