The 38-year-old Swedish striker has spent the past 18 months in MLS but his contract with Galaxy expires at the end of the year and he has been linked with a host of European clubs.
Ibrahimovic played for Milan between 2010 and 2012, scoring 42 goals in 61 league appearances, and Garber said he was on his way back to Serie A.
"Zlatan is such an interesting guy," he told ESPN. "He keeps my hands full and my inbox full, but he's a thrill-a-minute.
He is a 38-year-old guy who is being recruited by AC Milan, one of the top clubs in the world.
Ibrahamovic was named in the MLS Best XI in 2018 and 2019 after netting 53 goals in the competition.
His season with Galaxy ended after they suffered a 5-3 defeat by local rivals Los Angeles Football Club in the MLS Cup Western Conference semi-finals last month.