Essex leg-spinner Danish Kaneria will miss the first three weeks of the County Championship season in favour of Pakistan's domestic Pentangular Cup.
The Pakistan Cricket Board has confirmed the 29-year-old will represent the Sindh Dolphins in the competition, which runs from April 17-27.
The tournament will give players the chance to impress selectors ahead of Pakistan's tour of England this summer.
Essex chief executive David East admits the loss of Kaneria, who will not arrive in England until April 29, is a blow for his side.
"We were originally hoping to have Danish available for our first game on Friday, April 9 and the delay in his arrival is obviously disappointing," said East.
"We understand that this competition will help inform the decisions of the PCB prior to their tour of England and that it is viewed as an important opportunity for all Test and one-day international cricketers in Pakistan to impress the selectors.
"Danish is of course an important member of our side, but we must respect the primacy of the PCB and Danish's wish to be part of this event."