Abdalla, 20, who scored the winning goal in Egypt’s opening match, was diagnosed with a tear in his anterior thigh muscle following medical scans, the Egyptian Football Association (EFA) said in a statement on Tuesday.
He sustained the injury during the team’s goalless draw with Zambia in the third round of group matches.
His absence is a fresh blow to the young Pharaohs, who have recorded just one win from three games in the continental tournament they are hosting.
The team suffered a heavy 4-1 defeat to Sierra Leone before being held to a frustrating draw by Zambia.
The hosts currently sit second in the five-team group with four points from three matches.
Sierra Leone lead with seven points; South Africa are third with three; and Zambia have two points from two games.
Tanzania, who have played twice, remain without a point.
After a promising start, Egypt’s campaign has faltered. Coach Osama Nabih now faces a must-win scenario against Tanzania without one of his key attacking options.
The top two teams in the group will advance to the knockout stage of the tournament, which also serves as a qualifier for the FIFA U-20 World Cup.
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