Sporting and Atletico meet in the first-leg of their Europa League quarterfinal tie, with Piccini's clash against Costa a key duel.
The Italian said, "I know that their defence is impressive, it's very difficult to score against, they have good numbers.
"And above all, they have unpredictable players with a goal in them. And now there is Costa, who, apart from being a forward, is also the first defender, he does not stop working ... But we have worked on everything and we are ready."