Leg-spinner Shadab Khan has recovered from the infection and will be flying to England soon, sources said, adding: "Yasir Shah, who was included in the team, will return to Pakistan. Meanwhile, chances of Mohammad Amir's inclusion in the World Cup are diminishing after he was diagnosed with chicken pox which makes it unlikely that he would be able to play the ongoing ODI series against England.
Amir was not named in the initially announced World Cup squad but was included in the side to face England in the ODI series which was a gateway to make a case for himself for World Cup selection.
The deadline to make changes in the World Cup lineup is May 23. After the deadline is expired, a player has to obtain a medical certificate from ICC's technical committee before joining the final team.
Chief Selector Inzamam-ul-Haq said, "We have received positive reports about the fitness of Shadab Khan and hope that he will be fit in time for the World Cup."