Foster, who works at the bowling assessment centre in Perth, has helped some Pakistani bowlers correct their actions and pass biomechanics test, said that he would have preferred Ajmal since quality spin would play a decisive role in Australia and New Zealand.
Foster, who worked with Pakistan in three stints between 2001 and 2004 said he was surprised the team didn't opt for Ajmal even after he had been cleared in the ICC bowling assessment test.
"Ajmal has proven himself to be the best spinner in World cricket in all forms of the game so why, unless he is injured, wouldn't you select him?" Foster, who has worked with Sri Lanka's Muttiah Muralitharan and recently Sachithra Senanayake, asked.
In the absence of key spinners, Foster said the enigmatic Shahid Afridi would play a vital role for Pakistan.
More From This Section
Foster said he saw no reason why Pakistan would not pick Ajmal despite him not having played international cricket since August 2014.
Interestingly the Pakistan Cricket Board had given the tour selection committee the option of waiting for a day for Ajmal's test result to come out and then deciding on a replacement for Hafeez.
But the tour selectors decided to call up left-arm pacer, Rahat Ali, who has played just a single one-dayer in June, 2012.
Not picked for the World Cup, Ajmal has taken up a lucrative pundit role for a television channel during the mega-event.