Mohamed Salah will travel to Spain for treatment on his injured shoulder on Tuesday, according to the Egyptian Football Association.
The Liverpool star went off in tears after half an hour of his side's 3-1 Champions League final defeat to Real Madrid, having hurt his shoulder when falling awkwardly under a challenge from Sergio Ramos on Saturday.
Liverpool manager Jurgen Klopp said the problem looked "really serious" and, although he was eager to wait for tests, he admitted Salah's prospects of going to Russia were in jeopardy.
The Egyptian FA have since moved to calm fears he will miss the World Cup, claiming tests have shown the injury is not as bad as first suspected.