M'Baye Niang admits moving to AC Milan has forced him to grow up quickly.
The striker was snapped up from Caen last summer.
"At Caen people told me that I was too good, that I was a phenomenon," the striker told France Football.
"After a while, you inadvertently relax and don't work as hard. You can't do that here at Milan.
"There are stronger players than me in attack and if you don't train hard then you don't play, you just become the sixth attacker."