Angry AC Milan fans vented their frustration at the Italian giants\' 3-1 home defeat to Fiorentina by surrounding the car of Alexandre Pato and threatening the Brazilian striker, a report said Tuesday. Pato recently returned to Milan\'s first team following an injury lay-off and scored his first goal of the season in a 1-1 Champions League draw at home to Malaga on Tuesday. But his penalty miss the Fiorentina defeat at the San Siro on Sunday was seen by some fans as a costly mistake. According to Corriere dello Sport newspaper a group of angry Milan fans waiting for Pato to leave the stadium surrounded and banged on his car and launched verbal threats at the Brazilian. Pato, who is in a relationship with Barbara Berlusconi, the daughter of current AC Milan owner Silvio Berlusconi, earned the penalty on the half hour as Fiorentina led 1-0 but sent his effort from the spot over the crossbar.La Viola went on to take a 2-0 lead and after Pato was substituted at half-time in favour of Giampaolo Pazzini the Italian reduced arrears only for Mounir El Hamdaoui to score a superb third goal for the visitors. Victory could have propelled Milan up the Serie A table but instead the Rossoneri were left in 13th place, 17 points behind leaders Juventus. AC Milan moved to quash the report, saying in a statement: \"A.C. Milan categorically denies reports claiming Pato has been subject to aggressive behaviour and threats after the Milan-Fiorentina game.\" Milan\'s worst start to the season in living memory comes two years after coach Massimiliano Allegri steered them to the title in his first year in charge and a runner-up place behind Juve last season. Allegri said after the game: \"I\'m very disappointed because we had a chance to jump up the table into sixth place and start to put things in order. \"You can’t find yourself 2-0 down after the first half and we have to work on that. I don\'t know how it would have ended had Pato scored the penalty.\" Allegri\'s own position falls under the microscope several times a week, but on Monday the embattled coach was given crucial backing by Berlusconi. A Milan statement on Monday said: \"A long meeting was held yesterday evening (Sunday) with Adriano Galliani, Milan CEO, and President Berlusconi to discuss the future of the club. \"Massimiliano Allegri joined the two later for a detailed analysis of the current technical situation. Mr Berlusconi confirmed his complete faith in the coach... \"The aim remains to climb up the table with Allegri at the helm.\"