Barcelona top the group and go into this game after winning four of their five matches in Europe. However, Benfica are battling it out with Celtic for the runners-up position, and are on a recent run of seven successive wins.
And the 25-year-old is under no illusions of the threat the Portuguese will carry when they meet at Camp Nou on Wednesday.
"They have a very attack-minded team, with players like [Pablo] Aimar and [Oscar] Cardozo. They are very skilful and will be coming here to win,” he told reporters.
When attention turned to the domestic form of Barca, the Spain international responded in a positive manner.
He said: “The good start to the season gives us confidence but nothing has been decided yet.
“Tito [Vilanova] has done a great job since he came in and he is very brave. After all he has been through, this should be child’s play for him,” said the defender.
Pique, obviously worried about the length of time that the success will be at the Catalan club, concluded: “We must learn to live in this euphoria but at the same time be prepared for when we do not win everything.”