The two teams are set to battle it out for three points in a matchday seven fixture at MAPEI Stadium - Citta del Tricolore.
It would be a memorable game for Boateng, who had two separate spells with the Rossoneri between 2010 and 2016.
“Milan is the team I still support and have in my heart," Boateng told SportWeek.
"If I score against them, I will not celebrate, as I have too much respect for those club colours."
Should Sassuolo emerge victorious on Sunday, a lot would likely depend on Boateng, who has turned out to be the club's most influential man this campaign.
The 31-year-old has registered three goals in five league appearances for the Neroverdi so far following a summer move from German outfit Eintracht Frankfurt.
“I don’t think I’ve been reborn at Sassuolo, because I was never dead," Boateng, who has been deployed in an unusual No.9 role at Sassuolo, said.
"I wanted to come back to Italy and be close to the city of Milan, where I’ll go and live with my wife Melissa Satta and son Maddox after I retire."
Boateng initially joined Milan on loan in 2010 and a permanent deal saw him continue his time with the club until 2013.
Following a troubling time with German side Schalke 04, Boateng returned to the Rossoneri for a six-month spell in 2016.