Ganna established himself as the top triallist in the world this year and will look to balance preparation for the rescheduled Olympics alongside his domestique duties on the road next season.
The 24-year-old won four stages at the Giro d'Italia, set a course record in the Tirreno-Adriatico and claimed the world time trial title on home soil in Imola.
His impressive list of accomplishments also includes the Individual Pursuit rainbow jersey and Cassani believes the Ineos-Grenadiers rider will still contend for more despite his crammed 2021 calendar.
"Filippo has made a huge leap forward," Cassani told Het Nieuwsblad.
"To such an extent that next summer in Tokyo he will also be a medal candidate in the individual time trial.
"[Targeting the Team Pursuit] is still the case. Filippo is part of a project started four years ago by Marco Villa, coach of the track team. That project will not be abandoned because Filippo suddenly has the chance as a time trial rider.
"These guys have made tremendous progress over the past four years, took bronze at the World Championships three years in a row, and now also want Olympic honours.
"That's what Filippo wants. He doesn't want to abandon his teammates.
"It gets complicated, [however]. Not so much in Tokyo itself, but in the preparation.
"The Team Pursuit is a discipline that requires necessary training to become 'automatic'. You can't race on the road for a whole season and then suddenly switch to the Team Pursuit.
"In the last month before Tokyo you'll have to train on the track, so it won't be easy to create a good programme towards Tokyo. We'll talk to Ineos about it soon."
"What worries me more is the course of the time trial," Cassani added, with the 44-kilometre race based around the Fuji International Speedway.
"It's a lot harder than the Giro's hilly TT to Valdobbiadene.
"A gold for [Remco] Evenepoel and silver for Ganna? Sorry, but if we go, we go for gold."
The 2021 Games are currently scheduled to commence on July 23 and will run until August 8.