On Monday, the reigning Serie A champions took the lead against title rivals Roma, who had been reduced to 10 men.
However, just when it seemed Juve would close out the win and extend their lead at the top of the table to 12 points, Roma found an equaliser through Seydou Keita 12 minutes from time.
Juve still hold a commanding nine-point advantage with 13 games remaining, but, as they turn to their attentions to the Coppa, Allegri has demanded a better display.
"We need to improve, as sometimes we lose sharpness and focus," he said.
"We are still a long way off our objective and have conceded too many goals recently. We also have to improve in our control of the game when in front."
Although Allegri was disappointed with the draw against Roma, Juve have lost only once in their past 23 games in all competitions - and that was after a penalty shootout against Napoli in the Super Cup.
Meanwhile, Fiorentina - who lost out to Napoli in the final of last year's Coppa - are in fine form themselves and come into this meeting at Juventus Stadium on the back of a 12-match unbeaten run in all competitions.
The last of those outings saw Vincenzo Montella's side triumph 1-0 at Inter, a victory which left them fifth in Serie A, just three points off a UEFA Champions League qualification spot.
Mohamed Salah came off the bench to score the winner at San Siro on Sunday, and Montella was quick to praise the Egyptian, who has netted three goals in four appearances since joining on loan from Chelsea.
"I wanted to make the most of Salah's extraordinary form, that is why I chose him ahead of Alberto Gilardino," Montella said.
"I know that when a player is going through that kind of form, it's the duty of a coach to encourage it.
"I think he can play any position in attack. He attacks the space well and is very good at getting straight into the tempo of a game when coming off the bench."
Juve's influential playmaker Andrea Pirlo missed the meeting against Roma with a calf problem and remains a doubt.
For the visitors, Nenad Tomovic suffered a head injury against Inter and is thought unlikely to play, while Stefan Savic and Khouma Babacar are struggling with muscular problems and are being monitored.
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