Star Australian all-rounder Ellyse Perry will watch tomorrow's World Cup semi-final against the West Indies from the sidelines after failing to overcome a back complaint.

In a painful repeat of the 2020 T20 World Cup — when a hamstring injury kept her out of the finals — Perry is again an onlooker as a major tournament reaches the business end.

Perry suffered back spasms in last Tuesday's group stage win over South Africa and sat out training for a week in the hope of recovering.

However, captain Meg Lanning said after training on Monday it was clear Perry wouldn't be able to line up against West Indies in Wellington.

"Unfortunately she just ran out of time to prove her fitness," Lanning said.

"She batted a little bit in the nets yesterday and felt OK, but she just wasn't in a position unfortunately to be able to perform at the level needed.

"We will go in without her tomorrow and we'll keep assessing her if we are to progress in the tournament.

"Unfortunate for her and the team, obviously a big blow, but we feel like we've got some good depth to be able to cover it and we're going to have to do that tomorrow."

Perry remains in the frame for a start in the World Cup final on Sunday, should Australia win through, but Lanning was not of a mind to speculate on her availability.

"The team and squad is very focused on tomorrow and making sure that we're putting out our best game because everything else is irrelevant," she said.

Perry was player of the match in Australia's group stage win over West Indies a fortnight ago, taking 3-22 to skittle the top order.

Since then, the 31-year-old has struggled, bowling a 12-ball over against India with six wides, and an awful beamer in a short spell against South Africa before retiring hurt.

Lanning reported no other injury problems, with Darcie Brown near certain to return to the team to boost the bowling stocks.

The match begins at 11am local time (9am AEDT) at Wellington's Basin Reserve on Wednesday.

AAP