Milan stick with the 4-3-3, Theo Hernandez, Krzysztof Piatek and Rafael Leao, while Fiorentina have Dalbert, Federico Chiesa and Franck Ribery.
It kicks off at San Siro at 19.45 UK time (18.45 GMT).
There are already rumours Marco Giampaolo is hanging by a thread after losing three of the opening five rounds, including a midweek 2-1 defeat at Torino, where they had been leading and conceded two goals in five minutes.
The Coach sticks with the same XI that lost that game, because for an hour it had been the best Milan performance of the season.
He has scrapped his 4-3-1-2 approach for a more classic 4-3-3, with Suso and Rafael Leao flanking Piatek.
Ismael Bennacer and Theo Hernandez are also preferred to old guard Lucas Biglia and Ricardo Rodriguez.
Mattia Caldara is the only injury absentee, with Pepe Reina suspended after a red card for dissent off the bench in Torino.
Fiorentina finally ended their 18-round winless streak on Wednesday with a 2-1 victory over Sampdoria and it’s a special trip for Vincenzo Montella.
He was on the Rossoneri bench from the summer of 2016 to November 2017 and won their only piece of silverware since 2011, namely the Italian Super Cup victory over Juventus on penalties in December 2016.
The Viola brought in many new faces this season, above all Franck Ribery, and the 36-year-old has already made his mark with a goal in the 2-2 draw with Atalanta.
He partners Chiesa in something of a free role, with Pol Lirola and Henrique Dalbert on the wings, but Gaetano Castrovilli is being tipped for his maiden Italy call-up.
German Pezzella was approached by Milan this summer, but confirmed he turned down the move to stay with Fiorentina.
Meanwhile, ex-Milan star Kevin-Prince Boateng is once again on the bench.
Milan: G Donnarumma; Calabria, Musacchio, Romagnoli, Theo Hernandez; Kessie, Bennacer, Calhanoglu; Suso, Piatek, Leao
Milan bench: A Donnarumma, Conti, Duarte, Gabbia, Rodriguez, Biglia, Bonaventura, Krunic, Paqueta, Borini, Castillejo, Rebic
Fiorentina: Dragowski; Milenkovic, Pezzella, Caceres; Lirola, Pulgar, Badelj, Castrovilli, Dalbert; Ribery, Chiesa
Fiorentina bench: Terraciano, Ranieri, Boateng, Sottil, Cristoforo, Ceccherini, Ghezzal, Venuti, Benassi, Zurkowski, Vlahovic, Terzi
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