Alex, Zapata and De Sciglio trained on Friday with the rest of the squad.
The AC Milan Youth Sector continues to be a vital resource for the national teams.
Menez and Mexes took part in a hangout on Google+ on Thursday.
Special offer of match tickets and Milan shirts for the under-14s.
The rossoneri's next seven fixtures in Serie A.
The players trained the day after the friendly victory over Reggiana.