Pat Brown, the 21-year-old seamer, has been ruled out of all cricket for the winter after suffering a second stress fracture of the lower back in as many years.
Brown, who enjoyed a breakthrough season in 2018 when he took 31 T20 wickets for Worcestershire to finish as the Vitality Blast's leading wicket-taker, was unable to play franchise cricket last winter after playing through pain towards the end of the county season.
He developed a recurrence of the symptoms while preparing to play for Melbourne Stars, and a scan revealed a partial stress fracture.
Brown was due to replace Dale Steyn as the Stars' overseas player in time for Wednesday's game against the Thunder, but will miss the whole competition and return to the UK to start his rehabilitation.
He will also miss the white-ball leg of England's South Africa tour, having been named in both the ODI and T20I squads. Brown had impressed in his maiden series in New Zealand, taking three important wickets despite conceding 9.84 runs per over, but his chances of being named in their squad for the T20 World Cup in Australia this October are likely to suffer due to his injury.
England will name a replacement for Brown in due course, while the Stars could hand another opportunity to Haris Rauf, the Pakistan fast bowler who starred during his three appearances as Steyn's replacement.
"Gutted to be ruled out of the Big Bash and England's white-ball tour of South Africa with a stress fracture," Brown tweeted. "Will be doing everything to get back on the park as soon as possible."
"It's really disappointing for Pat," said Trent Woodhill, the Stars' list manager. "We were very excited to have him on board this season to replace Dale Steyn and it's disappointing we won't get to see him in action for the Stars.
"It's been great having him around the group and we've enjoyed welcoming him into the Stars family. We wish him a speedy recovery and hopefully we can work on seeing him in green in the future."