The Egyptian Football Association (EFA) announced on Thursday that Ashour spent a night in the hospital after sustaining a mild concussion during training on Wednesday.
However, his participation in the upcoming match remains uncertain.
The 25-year-old midfielder, who was benched in the Group opener against Mozambique, started in the other two games and delivered convincing performances.
Despite a slow start, Egypt has already secured a place in the round of 16 after drawing in all three group stage matches.
Injury concerns have also affected the team, with Liverpool star Mohamed Salah and Al Ahly goalkeeper Mohamed El-Shennawy having left the Pharaohs' squad due to injuries.
Salah has to complete his rehabilitation program at his Premier League club to rejoin the national team if they reach the final.
El-Shennawy, on the other hand, will be sidelined for around four months due to a dislocated shoulder.
Check the AFCON matches and standings
Check the AFCON stats
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)