Busio, 19, holds Italian citizenship through his father, which would allow him to qualify as a domestic player in Italy and which has increased interest from Serie A teams.
MLSSoccer.com reported in April that two Serie A clubs made bids last winter and both were rejected. Sources also told ESPN that prior to the 2020 season, Kansas City rejected a $4 million bid from Fiorentina.
A U.S. youth international at the under-15, under-17 and under-20 levels, Busio signed a Homegrown contract with SKC in August of 2017.
He has been a steady presence in the Kansas City lineup since the start of the 2019 campaign. He's shown versatility as well, playing as a deep-lying midfielder, attacking midfielder and forward.
All told he has made 63 league and cup appearances, scoring eight goals, including two this season.