The Gialloblu - a surprise package earlier in the Serie A season and for a long time contenders for a Europa League place - have crashed down to 10th place in the table on the back of four straight defeats.
Furthermore, no one has scored for Verona in their last 450 minutes of action.
Mandorlini's suspicion is that his players feel they have nothing left to play for since they clinched survival by reaching 40 points, and he is therefore urging them to prove him wrong against Genoa on Sunday.
"Everyone is desperate to get that win that would give us enthusiasm and confidence," he told the Corriere dello Sport.
"It won't fall for us from heaven, though, we have to go out and get it.
"Every game offers an opportunity to start again but (Genoa) are probably better than us. We will try to make the most of the challenge.
"We have done some good things so far this season but this has been a very difficult time."
Midfielder Romulo is suspended after picking up his fourth yellow card of the season during Wednesday's 1-0 defeat at Cagliari while Juan Gomez Taleb is sidelined with a knee injury.
Genoa players Matuzalem, Antonio Donnarumma, Sime Vrsaljko, Luca Antonini and Juraj Kucka will all miss the trip to the Stadio Marc'Antonio Bentegodi through injury while defender Daniele Portanova is banned.
If Verona have perhaps peaked too soon, Genoa still need one more point to reach the fabled 40-mark and effectively book themselves another season in the top flight.
Returning coach Gian Piero Gasperini has dragged the Grifone out of the relegation zone and into mid-table and, after overseeing an impressive 2-0 victory over Lazio in midweek, he is looking forward to seeing more shoots of progress.
"The players deserved the three points," he said. "I like the way the team struggled to get the result despite all the absences through injury. We improved with every passing minute.
"For me it has been a real pleasure to watch this team improving game by game."