Leao's work ethic has been questioned as he's spent time on the bench.
“Clearly I do not agree with that,” Leao told reporters from the Portugal camp.
“I have been having a great season at Milan but, like everyone else, there are ups and downs. The campaign has only just started. Look, I know that I am not the perfect player and sometimes I can do much better.
“I am not shaken by this criticism, I have people who help me to improve and those are the ones I have to listen to. This criticism just spurs me on to respond on the pitch.”
On Fonseca, he continued: “These things happen during the season, I have nothing against him and he has nothing against me. It’s all settled. I don’t like being on the bench, obviously, but he makes the decisions and I as a player have to respect the coach.
“When I step onto the pitch, I have to do my best to help the team.”