Both teams cannot afford to lose the encounter.
Marchisio said: "There is no one player in particular at Chelsea that we have to worry about – Chelsea are European champions and they have big players.
“Oscar played a great game in the first match and he’s a great talent but we must not focus on one player.
“We’ll have to be very careful and very focused. We have the best attack and best defence. I think we can do very well.”