Liverpool forward Mohamed Salah has a “proper tear in his hamstring”, says assistant manager Pep Lijnders.
Salah, 31, was replaced during Egypt’s 2-2 draw with Ghana in the Africa Cup of Nations in Ivory Coast on Thursday.
He watched from the stands as Egypt reached the last 16 thanks to a dramatic 2-2 draw with Cape Verde’ on Monday.
“It’s expected [he will] return in three to four weeks if everything goes smooth,” said Lijnders.
“It will go smooth and it will go right because of how we’ve treated his body before.”
Liverpool said Salah will return to the club on Wednesday for an “intensive rehabilitation programme”.
They said his injury was “worse than first feared”, but he will be treated with a “view to being back in action as soon as possible for club and country, giving him the best chance to return to compete at Afcon”.
On Sunday Egypt play the runners-up in Group F for a place in the quarter-finals. The final takes place on 8 February.
On Sunday Liverpool manager Jurgen Klopp said it “makes sense” for Salah to do his rehabilitation at the club and rejoin Egypt if he recovers in time and they remain in the competition.
“I always said before what I’m really happy about is the medical team of Egypt and the medical team of Liverpool really worked together and were in close contact and both made this decision,” said Lijnders.
“It’s an example of how international football and club football should operate to put the player in the centre.”
Egypt’s record appearance-maker Ahmed Hassan has said Salah should stay with the team “even if he only had one leg to stand on”.
“The one you should never doubt the commitment of is Mo Salah,” said Lijnders.
“I know the country is devastated to lose him. He is massive. The only reason ours and their medical team decided for him to come back is to give the best chance to make the final if Egypt reach it.”
The most recent of Egypt’s seven Africa Cup of Nations titles came in 2010, a year before Salah made his debut. Egypt were runners-up in 2017 and 2021.
Salah scored a late penalty to help Egypt draw 2-2 with Mozambique in their opening game.
He said this week that Egypt will win the Africa Cup of Nations “sooner or later”.
“I would love to win it,” he said. “It will happen somehow – that is what I believe. Whatever I believe, I achieve.
“I have won everything possible but this one, not yet. Everybody knows what it means to any player to win an Africa Cup.”