The Pharaohs face Cape Verde on Monday night before a potential last-16 tie next weekend, should they qualify. A pair of draws have left them requiring a result in Abidjan to at least secure a spot as a best third-placed team.
Should Egypt be knocked out at the end of the group stage, Salah will return to Liverpool while carrying the injury. The Reds face Norwich and Chelsea towards the end of the month, games which he appears set to miss even if his country departs AFCON early.
A statement from the Egypt FA on Friday night confirmed the result of scans on the winger's issue.
"Mohamed Salah has suffered a muscle strain in his back and will miss two matches," it read.
Liverpool boss Jurgen Klopp spoke with Salah following the Ghana draw and admitted it was a "shock" to see him go down.
He told reporters: "I spoke with him last night and how it was. They are doing further assessments now and then we will know more.
"In that moment it was a shock and couldn't see why he was hit by something so intense. You have these kind of hamstring injuries in a different way.
"He felt it and we know how rarely Mo goes off, or needs to go off, so it is definitely something but we will see. I don't have any more information right now."