Marino appeared at a pre-trial hearing on Monday - the same day his successor, Virginia Raggi, began her tenure in charge of the city.
During the hearing, Marino's lawyers asked for an expedited trial, meaning judges will reach their verdict in just one day, which has been scheduled for September 29th.
Under the Italian system, the punishment for anyone found guilty during a fast-track trial is automatically reduced by one third.
“The hearing went as well as we hoped,” Marino's lawyer, Enzo Musco, told Corriere.
Marino was removed from office last October amid a scandal dubbed 'Dinnergate' by the Italian media.
The former mayor stands accused of using the city hall credit card to pay for €12,716 worth of personal dinners around Italy.
Marino has claimed that the contested dinners – all 56 of them – were carried out while he was on official business.
But the prosecution allege the dinners were consumed with family and friends, highlighting that several of them were enjoyed on national holidays.
Aside from the dinners, Prosecutors are also accusing Marino, a former surgeon, of making illegal payments to members of his own non-profit association while in office.
The association, named Imagine, works to provide medical aid in Congo and Honduras, but the prosecution claims a series of payments were made to staff between 2012 and 2014 for work which was never carried out.
“I wish the new mayor the best of luck,” Marino told reporters as he left court.