"I know the responsibility I am taking in representing a club like Newcastle United and to tell the truth I will be a bit anxious to begin with," he said today.
"But having said that, I am confident I will not disappoint anyone at St James's Park. I have confidence in my ability, otherwise I would never have signed for a club like Newcastle United.
"When I agreed to join Newcastle United I knew that I would be playing for one of the best teams in England and in the best league in Europe and that I would be working with Sir Bobby Robson.
"Of course Sir Bobby is well known and respected in Portugal after his success with both Porto and my old club Sporting Lisbon.
"I am sure I will learn quite a bit from him and develop into the player he expects me to be."