MILAN: AC Milan captain Riccardo Montolivo will undergo knee surgery after sustaining a knee injury on international duty with Italy, the club said on Friday.

The 31-year-old midfielder, who was substituted in the first half of Thursday's 1-1 World Cup qualifying draw with Spain, is set to be out of action for about six months, local media reported.

Montolivo has been plagued by injuries in recent seasons, missing the 2014 World Cup and Euro 2016.

He will be replaced by uncapped Torino midfielder Marco Benassi in the squad for Sunday's qualifier against Macedonia, the Italian Football Association said on its website (www.figc.it).