Maresca was forced to completely rip up his system in the opening minutes after losing his goalkeeper.
He later said after the 2-1 defeat: "For me personally, it's quite easy in terms of after three-four minutes, it was rough for the way the red card became difficult not only for Chelsea, it became difficult for any club.
"For sure we could have started the game better, then the red card (for Casmeiro) gave us the chance to come back in the game. We had two-three moments inside the box, but all the game changed after the red card, all the planning and everything, it doesn't exist anymore."
Maresca continued: "The reason why we changed Pedro (Neto) and Estevao was because they attack with the five players always, and we defend with the four, and we can defend with the four when we are 11 vs 11, but 11 against them, I think we need to defend on the width, so we decided to go with the back five, this is the reason why.
"And then the other one, Garna (Alejandro Garnacho), he was ready to go on, but then Wes (Fofana) asked for the change, because he was tired after a long time, so we changed and we decided to go for Tyrique (George), and the idea was to give Garnacho minutes."