#8 Alessandro Matri (2013-14)
Having developed a reputation of being a hardworking striker who can play multiple positions, Alessandro Matri earned a move to AC Milan after two fruitful spells at Cagliari and Juventus. With the Rossoneri, however, the Italian striker had a torrid time as nothing went right for him despite his best efforts.
Upon receiving the #9 shirt vacated by Pato, Matri succumbed to the pressure that comes with it and departed the club after a solitary season. Despite signing a four-year contract, he was shipped off to Fiorentina on loan at the end of the 13/14 season and had just one goal to show for his time at Milan.
#7 Mattia Destro (2014-15)
Regarded as one of the best young strikers in Italy, Mattia Destro was banging in the goals for Roma and was courted by the big boys, with Real Madrid reportedly one of the clubs interested in securing his services at the time. As AC Milan were undergoing a crisis upfront, Destro was drafted in as an emergency loan signing in January 2015 and despite that, he was given the vacant #9 shirt left behind by Matri.
In 15 appearances for the club, Destro scored just 3 goals and failed to make his loan move permanent, meaning yet another striker with the #9 shirt had not delivered at the San Siro. The Italian striker left the club at the end of the season and joined Bologna, where he revived his career and found his scoring boots once again.