Aussies face unknown test in WC semi-final

Momentum from their victory over England should help Australia deal with the unknown package Afghanistan presents in their Under-19 Cricket World Cup semi-final.

Australian skipper Jason Sangha admits his side knows little about the Afghan players or the style of cricket to expect in Christchurch on Monday.

"We don't know too much about Afghanistan but the best part about these World Cups is that they are a bit unexpected," Sangha said.

"If we focus on the Australian way, playing aggressive and fearless cricket, then we should be sweet.

"We've got a lot of confidence and momentum from the England game (quarter-final win) but that's in the past."

Sangha, the 18-year-old NSW Blues rookie, was one of Australia's stars in the quarter-final win, scoring 58 runs and taking three spectacular catches at first slip.

"I feel towards the back of the tournament we are starting to play our best cricket," he said.

"What we learned from the last game is that we can win from anywhere."

Allrounder Aaron Hardie is a new addition to the squad, arriving in New Zealand on Saturday to replace injured fast bowler Jason Ralston in the Hagley Oval clash.

Hardie impressed for Australia in a three-match Youth ODI Series against Pakistan in Melbourne in December.

The winner of Monday's semi-final moves into the tournament final on February 3 in Tauranga and will face the winner of the India-Pakistan semi.

Australia last played Afghanistan at under-19 level in a 2014 World Cup group-stage clash, losing by 36 runs.