Kaneria took 75 county championship wickets for Essex in 2009
Danish Kaneria is set to miss the first five games of Essex's season due to additional commitments in Pakistan.
The leg-spinner, 29, was due to begin the season with Essex, before joining Pakistan's touring side of England.
However, the Pakistan Cricket Board (PCB) has confirmed he will play for the Sindh Dolphins in their provincial Pentangular Cup between 17-27 April.
Essex chief executive David East said: "We respect the primacy of the PCB and Danish's wish to play in this event."
Kaneria is now expected to arrive in the UK until 29 April.
East admitted the news was "obviously disappointing", but added: "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."
Essex make their return to Division One of the County Championship when they host Hampshire on Friday.