Pakistan's best is yet to come and struggling skipper Babar Azam is due "something very special" in their Twenty20 World Cup semi-final against New Zealand on Wednesday, team mentor Matthew Hayden warned.

Former Australia opener Hayden, who was batting coach for Pakistan at the last World Cup and appointed team mentor for this edition, said they planned to make the most of their second chance.

"When the Netherlands beat South Africa it was a significant moment for us, a very significant moment for the team in general around reaching its potential," he said on the eve of the semi-final in Sydney.

"It has been a roller-coaster... but I really believe we have yet to play our best game, which is a huge threat to oppositions."

While Pakistan's bowling, led by Shaheen Shah Afridi, has been improving, their batting has been fragile, a concern against a top-class New Zealand attack led by Tim Southee, Trent Boult and Lockie Ferguson.

Azam's form in particular remains a worry with the opener managing just 39 runs in five matches.

Hayden said the skipper was due some "fireworks" and predicted they could come on Wednesday.

"There's no question Babar has been under some adversity but that will only make him an even greater player," he said.

"We know with the weather that when there's a lull, there's often a storm that follows, so look out rest of the world because I think we're about to see something very special from Babar."

New Zealand started their campaign this year with a massive 89-run win against the defending champions, also in Sydney, and Hayden said Pakistan were wary of the Black Caps.

"They got 200 on this particular wicket against Australia... New Zealand have some really destructive players and they can put you under pressure with the bat," he said.

"They've also got a terrific, well-balanced bowling attack.

New Zealand skipper Kane Williamson played down any significance in his team making 200-3 on the Sydney wicket, noting that they only managed 167-7 against Sri Lanka when they returned to the ground later in the tournament.

"We'll just be looking to focus on our cricket really and the plans that we are looking to execute and make sure we adjust to the conditions and try and play smart."

New Zealand followed up that first Sydney win with a six-wicket victory over Sri Lanka, with a washed-out game against Afghanistan in between. They lost by 20 runs to England before hammering Ireland to secure a semi-final place.

Williamson said the results counted for little when it came to the knockouts.

"Finals sport can go any way," he said. "Both teams match up pretty well, there's some similar trends, we've both been playing some good cricket.

"They've got an outstanding pace attack," he added. "Some really experienced players throughout their side, match winners, so real strength in their team."