Former Pakistan bowling coach and leading biomechanics expert, Daryl Foster, says quality spin would play a decisive role in Australia and New Zealand despite a popular notion that the wickets Down Under were conducive to pace bowling alone.

Foster, who worked with Pakistan in three stints between 2001 and 2004, said the perception among visiting teams of fast and bouncy pitches was true to some extent but often captains made the mistake of packing too many pacemen in the side.

Foster expressed his surprise over Pakistan not picking spin maestro Saeed Ajmal after the bowler was cleared by the International Cricket Council (ICC).

"I certainly would have picked Saeed Ajmal after Mohammad Hafeez, unfortunately, had to withdraw. Saeed is a match winner and if anything can upset teams like Australia, New Zealand and South Africa, who I regard as the favourites, it is good quality spin bowling. Visiting teams imagine that Australian and New Zealand wickets will all be fast and bouncy but that is not always the case. Quality spin bowling always has a decisive role to play," Foster told Dawn.com in an exclusive interview.

Foster said he saw no reason why Pakistan would not pick Ajmal despite him not having played international cricket since August 2014.

"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.

"Afridi is one of the key players in the tournament as he has that X-factor and he will be a very important cog in driving Pakistan's success. I wish him and the team the best of luck. "

Pakistan take on India in their World Cup opener on February 15 and Foster said while MS Dhoni's men held the edge, he wouldn't read to much into the recent fortunes of the two teams.

"It should be a great game in Adelaide on Sunday with India having a slight advantage seeing they are very well acclimatised to Australian conditions."

"I wouldn't worry too much about Pakistan's results in New Zealand in their two-match ODI series. New Zealand were very much match hardened coming off a competitive series against Sri Lanka whilst Pakistan had just arrived in the country."

Pakistan have never won a match against their neighbours at the World Cup, suffering five defeats dating back to 1992. That despite winning 72 of the other 121 One Day Internationals played against their old foes.

A 47,000-strong crowd is expected to be at the Adelaide Oval while the ICC has claimed it would be the most watched cricket match in history with an expected TV audience of over one billion.