The Nerazzurri were held to goalless draw by bottom club Catania on Sunday and are now winless in their last five games.
"All week the players sensed scepticism from the fans and media. These players are not accustomed to certain pressures and felt the lack of enthusiasm in the stands, as it almost felt as if we were playing in an empty stadium," he told Sky Sport Italia.
"Unfortunately, the breakthrough incident to score didn't arrive and the lads did better when the supporters were riled up a bit by going close to a goal. The atmosphere makes a difference, as anyone who played football will know.
"Our heads are not clear and therefore we don't make the right decisions and feel the pressure when making mistakes. I thought the team played in a more relaxed manner in Genoa, as they seemed tense at San Siro. With the atmosphere being what it is at the moment, the squad may well play better away from home. There's no point denying that."
Prior to this afternoon's match, Catania had not picked up a point away from home, having lost all 10 of their previous games away from the Stadio Angelo Massimino.