If Bakayoko impresses, Milan can sign him permanently for £35.7m - slightly less than the fee Chelsea paid Monaco for his services just a year ago.
Jorginho, N'Golo Kante and Ross Barkley started in Chelsea's midfield on Saturday, with Loftus-Cheek replacing Barkley in the 68th minute.
The 23-year-old, who is desperate for first-team football, has already jetted in to Milan to undergo a medical and is waiting for the final details to be sorted.
He also demonstrated his ability by converting a lovely penalty on his Premier League debut in the 3-0 win over Huddersfield on Saturday.
Bakayoko leaves Chelsea after making 29 Premier League appearances for the Blues but failing to recapture the form that prompted the London club to pay Monaco a reported £40 million for his services last summer.
The Italian didn't discuss Bakayoko's potential move after the clash but suggest it would take Chelsea a while to reach their best this season.
"I don't know about what happened in the past but now he has a good chance", Sarri said of the Brazil defender.
"On Monday four players from the World Cup arrived".
"Hopefully two months and not three".