كتب : وكالات
The Ahli midfielder grimaced in obvious pain after being pushed by an opponent in the second half of The Pharaohs' surprise 1-1 draw at home with Sierra Leone on Sunday.
Hassan was taken off 12 minutes from the final whistle of the 2012 Africa Cup of Nations opening qualifier, and underwent medical examinations later on.
It was confirmed that his injury requires surgery to repair the damaged ligament, which will result in a lengthy layoff.
"He will undergo an operation in Germany next week and the Egyptian FA will pay it," Ahli's chief doctor Ihab Ali told FilGoal.com.
Hassan, 35, earned his 175th international cap against Sierra Leone to move to within touching distance of becoming the world's most capped player.
He is two matches short of equaling the record of former Saudi Arabia keeper Mohammed Al-Deayea.