Afghanistan captain Gulbadin Naib is confident his unheralded side will not suffer from stage-fright when they play holders Australia in their World Cup opener.

Naib's team go into the tournament as 100-1 outsiders and few expect them to shock Australia in Bristol on Saturday.

When they met Australia at the 2015 World Cup in Perth, a 275-run defeat ensued as David Warner hit 178 in a total of 417 for six.

But Afghanistan cricket has undergone a steady improvement since that competition and the minnows start the tournament bolstered by a recent win over Pakistan in a warm-up fixture.

"We are very excited for tomorrow's game and the start of the tournament," Naib told reporters on Friday.

"The team has changed from four years ago, and the last couple of years we have improved very well in every department.

"We are just focusing on tomorrow. The World Cup is a big stage, and we are looking forward to doing our best."

Much is being made of Afghanistan's outstanding spin bowling contingent, with Rashid Khan, Mujeeb Ur Rahman and Mohammad Nabi all high of the one-day international bowling rankings.

Naib warned Australia his trio of twirlers could do some damage if the pitch is conducive to spin.

"We have a great spin department in our bowling attack, but it will depend on the wicket tomorrow," Naib added.

"I have a confidence in my team and players, especially with how we have prepared over the last 12 months.

"We beat Pakistan in our first warm-up game, so anything can happen.

"We know that Australia is a champion team, but we will giving 100 per cent."