AC Milan captain Massimo Ambrosini risks missing his side's UEFA Champions League round of 16 opener against FC Barcelona after being ruled out for a month with a thigh muscle injury.

The 35-year-old midfielder sustained the injury to his right thigh during Sunday's 0-0 Serie A draw at UC Sampdoria, with scans revealing the extent of the problem. Ambrosini's absence will be a blow to coach Massimiliano Allegri, who has lost his other holding midfielder, Nigel de Jong, for the rest of the season because of an Achilles tendon complaint.

Ambrosini has played 13 games in Serie A and two in the UEFA Champions League group stage this term. Milan take on Barcelona at San Siro on 20 February, with the return fixture at the Camp Nou scheduled for 12 March.

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