Man Utd's Anderson: I won't celebrate scoring against Porto
Brazil international Anderson then sealed an £18million switch to Manchester United two years later.
And although he is determined to KO his old team, he will not celebrate if he finally breaks his 67-game goalscoring duck at United.
He said: "I was very happy at Porto. They opened the door to my career in Europe.
"If I score I won't celebrate as I've enormous respect for them.
"It's going to be tough but we are the favourites. We want to win more titles and that's why we are going to knock Porto out."