The Portuguese side face Arsenal in the Champions League and Meireles admits their big challenge is to stop Fabregas.
Meireles said: “Cesc Fabregas is a big footballer and the is the key piece in Arsenal. We must stop him being a danger.
“Without Fabregas, I am convinced that Arsenal lose a big part of their percentage. Our mission is to make sure that we can stop Arsenal and go to London with a chance of going through.”