Inter have been criticised over their treatment of Coutinho, who many believe is more talented than Santos star Neymar.
"I began the season well," he told RaiSport. "Then, sadly, I got injured and that just halted things a bit. I need to work even harder. I can't complain about how things have gone this year. I played more football and earned people's trust. I still want to give more however.
"Do I see my future at Inter? Yes, I like it here, I'm happy. I want to improve and win trophies here."