I saw the match from the 20 min mark, and I too tried to observe as an impartial "scout".
"SOKRATIS" (as his jersey reads) played well, in fact even the FOX commentator seemed to be impressed with the first half. Sokratis was on the right side of a three man defensive line, and was against MUTU until aprox. the 80' when MUTU was substituted. The Fiorentina attack were trying to exploit Sokratis' side, but he kept his ground well, eventhough it was obvious in the 2nd half Fiorentina turned up the heat on Sokratis.
He looked a bit raw, but maybe more a lack of fitness/1st team experience. He closed down space well, never was beaten wide, or when dribbled at. He did seem a bit out of controll in the air, almost rag-doll-like in his arial challenges.
I think overall, he had a good showing, and the fact he made his Serie A debut against a good team like Fiorentina tells me that his manager believes in him as well.