Pakistan Cricket Board (PCB) official Saleem Altaf said today that Mushtaq had been hired for the tournament starting from October 7, but the contract would be reviewed after the tournament.
Pakistan's head coach is former England player Bob Woolmer, who has held the post since July 2004.
''The appointment of Mushtaq was a board decision,'' Altaf told Reuters when asked whether Woolmer was consulted.
''We have brought in Mushtaq since bowling coach Waqar Younis would only be available for a week of the tournament. He will be busy at our national cricket academy,'' he added.
The 36-year-old Mushtaq, who has made 52 Test and 144 One-day international appearances, was drafted into the Test squad in the home series against England towards the end of last year, but did not play.
He was later appointed as bowling consultant in the One-dayers and than bowling coach for the series against India earlier this year.
He has been playing for English county Sussex for the last three years with considerable success, and there was speculation he would be picked for the recent series in England, but he was overlooked.
Pakistan lost the Test series 3-0.
Altaf also said the Pakistan squad would set up a training camp in Jaipur, India for a week before its begins its Champions Trophy campaign on October 17.
''We are also planning some friendly matches before the tournament in India,'' he added.