The 22-year-old has accumulated five yellow cards in 12 Serie A matches so far this season, including one in the 1-1 draw against Fiorentina on Wednesday evening, and that he ruled him out of the clash with his former club.
“I feel for him, it is disappointing for him not be there, he wanted to be there,” Calabria told Milan TV.
“He is doing great things; I am happy for him.
“Surely his absence works in our favour but there are many great players at Sassuolo.
“We must be ready to react to their play in the best ways possible.
“We are Milan, we must aim high and win these games.”
Locatelli came through the AC Milan youth system but he moved on loan to Sassuolo in 2018 and was brought outright a year later.
The central midfielder also has earned six caps for Italy.