The agent of Napoli midfielder Marek Hamsik admits he's been hit by a form slump.

Hamsik wasn't at his best for defeat to Juventus on Friday night.

Juraj Venglos told Radio Crc: "For Napoli it is only the first defeat in A. The team is not tired but has faced a team as strong as Juventus.

"The Azzurri did well in the other challenges with Lazio, Roma and Inter. Against Juventus it was just a misstep: Marek has been playing all the games for a long time, it's clear that behind his performance there could be a factor, but at the moment it is not a physical problem, it is clear that he is not scoring and doing the best at the moment.

"I do not think it is influenced by the (Diego) Maradona record, at least from my point of view."