Pato may have been the match-winning hero in AC Milan\'s 2-1 Coppa Italia victory over Novara on Wednesday, but a day later he discovered he will face up to a month on the sidelines. Pato has been injury prone over the last two and a half seasons and he has suffered yet another problem having been diagnosed Thursday with a slight hamstring pull. Milan said he faces three to four weeks out. Having scored the winner ten minutes into extra-time against Novara, he was forced to leave the field in the second extra period after feeling a problem in his hamstring.