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.
And on Monday they said in a statement that the 25-year-old will be accompanied by Liverpool's medical staff to Spain to start an intensive period of rehabilitation.
Egypt's World Cup campaign kicks off against Uruguay on June 15.
— Egypt National Football Team (@Pharaohs) May 26, 2018
Photo Getty Images. Caption: Mohamed Salah receives treatment during the Champions League final