The striker is struggling for form and has scored only once since Mario Balotelli arrived.
"Stephan kept us afloat for a long time and without him we wouldn't even be third right now. Balotelli has a remarkable goals to games ratio, as do El Shaarawy and Giampaolo Pazzini.
"At the age of 20, a player can have some dips in form, especially as even without the goal he continues to work for the team. He is a great champion and must continue like this."