It is a serious blow to England's World Cup hopes, given the 28-year-old left-armer's fine form this year.

England are waiting for organisers to ratify his replacement.

Tymal Mills, another left-armer, and right-arm seamer Richard Gleeson are the pace bowlers in Australia as England's travelling reserves.

Confirmation of Topley's replacement could come on Thursday, with Mills, who himself has not played since August because of a toe injury, the most likely option.

The injury is also a cruel disappointment for Topley who has overcome serious setbacks in recent years.

He had four back stress fractures in five years, mostly recently in 2018, which led him to consider retirement.

But after regaining his place he has become a key player in England's white-ball sides and this year took his best figures for England in both T20 and one-day international cricket - 3-22, and an England record 6-24 - against India in the summer.

He had become a crucial part of England's bowling attack, operating effectively with the new ball and during the death overs.

England also lost batter Jonny Bairstow to a freak leg injury before the tournament, while Jofra Archer is a long-term injury absentee.

However, Jos Buttler's side have had an encouraging build-up to the tournament after a 4-3 series win in Pakistan and a 2-0 victory over hosts and defending champions Australia.

England face Afghanistan in Perth at 12:00 BST on Saturday.