Ahead of their clash with Scotland, Martinez was full of praise for Lukaku.
"I think Romelu is one of the modern footballers born with media attention: they followed him from the age of 16 in Belgium," said the coach.
"The media have always followed him: from the experience at Anderlecht with the participation in the Champions League until the transfer to Chelsea. Then he did well at West Brom before the move to Everton. Then came the big transfer to Manchester Untied and now at Inter.
"The Cagliari chants? Romelu is not affected by certain things, he is one of the most motivated boys: football is his life, he lives to score goals and be effective for Belgium and his team.
"Then it is true that he was sad about the episode he had to face, but I am sure that everyone in football will try to help him and the environment to eradicate this problem. For racism there must be no tolerance."