Jose Callejon fears the defeat to Shakhtar Donetsk shows “opponents study how Napoli play and know our systems.”
The Partenopei were beaten 2-1 in Ukraine for their opening Champions League group game, having also struggled to victories in Serie A past Atalanta and Bologna.
“The teams we play against study us carefully and know how we play, so they press us better and make it all more difficult,” the Spaniard told Mediaset Premium.
“They know our systems and we need to move the ball quicker, as that makes it tougher for the opposition to stop us.
“Tonight we were up against a side that pressed well and had a lot of quality in its passing, so at this level it’s going to be tough.”
Callejon was asked if Napoli played differently with Arkadiusz Milik starting in attack rather than Dries Mertens.
“Mertens is very talented, we all know that, but there are other players in the squad and it’s a long season, so rotation is necessary.
“When Milik plays, we have to help give him service, just as we do when Dries plays, so we are becoming more versatile.”