A run of just one defeat in 19 matches across all competitions left Fiorentina hopeful of a top-three finish in Serie A and subsequent Champions League football, as well as Coppa Italia glory.
However, Fiorentina's season unravelled in the space of five days. First a 3-0 defeat at home to Juventus last Tuesday saw them squander a 2-1 first-leg advantage to exit the Coppa.
It was the same scoreline in Sunday's league outing at Napoli, a loss that struck a blow to their Champions League ambitions and they now trail third-placed Roma by eight points with just eight matches remaining.
It remains to be seen if there will be any lasting psychological damage from those defeats, but Fiorentina must regroup quickly ahead of Thursday's encounter at the Olimpiyskiy National Sports Complex - which is subject to a partial stadium ban for the fixture due to racist behaviour of supporters in their last-16 home tie against Everton.
"We came from a 3-0 defeat at home against Juventus and now a 3-0 defeat against Napoli," Fiorentina captain Manuel Pasqual told reporters after the Napoli defeat.
"We want to react. We are an important team and we want to prove it to everyone."
With the promise of Champions League football on offer for the victors of Europe's secondary competition, Fiorentina will be desperate to return to form.
But they face a Dynamo side who are flying and remain top of the Ukrainian Premier League – unbeaten.
They head into the match on the back of a 2-2 draw against Zorya, though, and Rebrov is expecting a difficult encounter.
"We must concentrate on Fiorentina," he said. It will be a completely different game from the one played in the league [against Zorya].
"Fiorentina is a team that plays well in defence and on the counter-attack."
Dynamo are without the injured Yevhen Makarenko and Miguel Veloso, while Jose Maria Basanta is suspended for Fiorentina.
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