The 23-year-old spent the second half of the 2016-17 campaign on loan at San Siro after he was deemed surplus to requirements by Everton boss Ronald Koeman and impressed with a string of fine performances, scoring four goals in 17 Serie A appearances.
Milan are allegedly keen to sign the versatile former Barca attacker permanently, but they will have to be patient if they are to get their man.
"I cannot say much about Deulofeu's future," his agent Gines Carvajal told TMW.
"Everton and Barcelona are in charge, these two clubs will decide his future.
"We can only wait to see what happens. Milan could be an option, but it will be very difficult."
Deulofeu is owned by Everton, though his boyhood club Barcelona have an option to re-sign the winger and are considering bringing him back ahead of next season.
Only if Barcelona opt against signing the Spain international do Milan appear to have a shot of landing him on a permanent basis.