Leg-spinner Shadab Khan, who was ruled out of the upcoming England series following a viral infection, will return to Islamabad from London on Monday, the Pakistan Cricket Board (PCB) said on Saturday.

Shadab, according to the PCB statement, consulted Dr Patrick Kennedy, a recognised gastroenterologist and hepatologist over his health.

The spinner has been put on medication and advised "complete rest for two weeks", the statement notes.

He will undergo a round of blood tests in Lahore to ascertain whether he will be able to play in the upcoming ICC Cricket World Cup 2019.

The World Cup 2019 will begin on May 30, with Pakistan's first match scheduled against the West Indies on May 31 at Trent Bridge.

The selectors have already included Mohammad Amir and Asif Ali as additional players to the 15-man World Cup squad. Changes to the squad without needing ICC's permission can be made until May 23.

Pakistan's pre-World Cup tuneup series against England, comprising a T20I and five ODIs, will be played from May 5-19.