Vincenzo Montella's men reached the cup final after a 2-0 win over Udinese on Tuesday completed a 3-2 aggregate victory.
A victory over Inter at the Stadio Artemio Franchi would be another huge boost for Fiorentina, who are fourth on the table.
Walter Mazzarri's Inter side are fifth – eight points behind Fiorentina – and a loss would be a big blow to their European qualification hopes.
The loss of Giuseppe Rossi to a knee injury has hurt Montella's men, with the Italian striker having scored 14 goals in the league prior to going down.
But Montella's squad appears strong enough to cope with his absence.
Alessandro Matri – on loan from Milan – can start up front, while there are goals to be had from the likes of Borja Valero and Juan Manuel Vargas.
Inter broke a six-match winless run in all competitions last time out, edging strugglers Sassuolo 1-0 thanks to Walter Samuel's goal.
Mazzarri has been under pressure and criticised for not using his younger players more often, including the likes of Mateo Kovacic and Mauro Icardi.
The former Napoli coach is unfazed by the pressure on him and says his relationship with president Erick Thohir is strong.
"I have an excellent rapport with the president. If I had the chance to talk to him directly every day it would be better, but this is just extra motivation for me," Mazzarri told Radio Capital on Wednesday.
"We understand each other and there is reciprocal respect. That gives me the strength to continue my work.
"Inter had started on the right foot, then certain things happened which took us to this moment. We're not doing what we wanted to, aside from Sunday's victory over Sassuolo."
Inter have a good record against Fiorentina, having tasted defeat just once in the previous 17 meetings between the teams.
They desperately need to avoid defeat once more or could find themselves outside the top five come round's end.
