The official stopped short of claiming the referee favoured title-rivals Napoli after several controversial decisions against Genoa, but questioned why he had been selected
Guida controversially turned down several penalty appeals from Antonio Conte's men which meant the Italian champions dropped two points, which could allow fellow Scudetto contenders Napoli to close within three points at the top with a win on Sunday.
"The referee Guida is from Naples, so maybe that's why he felt under certain pressure," explained Marotta to reporters after the match.
"I am sure he is a good man, but if these referees are not assigned to the matches of clubs originating from their region, there has to be an underlying reason.
"I am just discussing this error. He's young, and being assigned to our game must have been difficult for him. Imagine the fallout if a Turin referee had taken charge of a Napoli match."