Blind played for De Boer at Ajax and has been linked with the Nerazzurri since his old manager took charge last week.
"I really like him (Blind) as a player, that's for sure," De Boer told Bein Sport.
"But he is very happy at the Red Devils and also played the Community Shield. I know his situation and I know that he is happy and plays with confidence, however, we will see in the future.
"I like to follow them as I do with Daley."