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 www.acmilan.com. "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 Champions League. They then face Parma, Lazio and Fionentina in Serie A before their return clash with Barca at the Nou Camp.