The allegations date back to a Serie A game between Napoli and Sampdoria in May 2010, when it is believed then-reserve team goalkeeper Matteo Gianello asked the duo to help rig the result.

If found guilty, Napoli could face a one-point deduction and a 100,000 euro fine, but Mazzarri believes Grava and Cannavaro are innocent with no punishment for them - or the club - required.

"I know the two guys (Grava & Cannavaro) and I trust them," he said.

"They said they didn't hear anything and that nothing has been said to them. I think they should be acquitted and no penalization for Napoli should be given.

"I don't know what the guys think, I keep hoping that the authorities will believe the words of both of them and that Napoli won't be penalized as a result."

After back-to-back defeats in Serie A, Napoli will be looking to bounce back against Bologna in their Coppa Italia clash on Wednesday.