The 20-year-old Italy international suffered a microfracture in his left foot during training last month.
"Next week I will undergo a scan on my foot," El Shaarawy told the club's official website.
"I don't think I will return to play until the return leg of the Champions League against Barcelona on November 6.
"I'm not used to being on the sidelines a lot but I'm recovering and I'm on the right path. I hope I can return to play as soon as possible."
AC Milan host Udinese this weekend before taking on Barca at the San Siro in the UEFA Champions League. #
They then face Parma, Lazio and Fionentina in Serie A before their return clash with Barca at the Nou Camp.