Larsen, who took charge of the Champions League semi-final first leg between Manchester United and Arsenal last year, said the Portuguese international is "always out to get a cheap free-kick, especially at home.
"We tended to talk in the referee's room before games about how he would go down easily. We know not to be biased, but we have to be prepared.
"He has a clean slate at the start of every game. When he would lie down after failing to win a free-kick, he would smile at me because he knew I didn't fall for his stunts."