Ronaldo kicked off his career with the Lisbon giants.
“It's a special game, they are a special team, they're got a good coach and it will be another special moment in my life. It's a privilege for me.
“Winning the Champions League again is a great challenge and I think at Real Madrid we have the opportunity to do it. We will take each game as it comes and we have to think about the group stage first of all, because in my opinion we have got a difficult group. We'll see how the competition develops. I'm thinking positively, it is possible to win it again."