Pakistan trio Salman Butt, Mohammad Asif and Mohammad Amir will miss Thursday's tour match against Somerset after being called to London by the Pakistan Cricket Board.
The three players are at the centre of the recent 'spot fixing' allegations and will be questioned by PCB chairman Ijaz Butt and his country's high commissioner on Thursday.
The questioning, part of the PCB's internal investigation into the allegations, was originally due to take place on Wednesday.
But the meeting has now been pushed back 24 hours, meaning skipper Butt and seamers Asif and Amir look certain to be unavailable for clash in Taunton.
"Three players - Butt, Asif and Aamer - are going to London. It is an internal investigation," team manager Yawar Saeed said.
The investigation comes following 'spot-fixing' allegations against the Pakistan team during the fourth Test against England at Lord's.
The News of the World alleged that some players had deliberately bowled no-balls during the match an attempt to defraud bookmakers.
Pakistan's tour of England is set to continue but Butt, Asif and Amir did not train with their team-mates at Taunton on Tuesday, instead staying behind in the team hotel.
Multiple inquiries into the allegations are ongoing, with Scotland Yard and the International Cricket Council conducting their own investigations.
Pakistan's Federal Investigation Agency, the highest law enforcement agency in the country, has also sent three officers to the UK.