Bethell's latest injury setback comes after a prolonged absence from international cricket. The 22-year-old has not played since England's ODI series against India in July and has now missed nearly five months of action.
The left-handed batter initially expected to recover within three to four weeks after experiencing knee soreness during the T20I series against India. However, further medical examinations revealed a chondral defect, or cartilage damage, in his right knee, which required surgery.
According to an England team spokesperson, Bethell suffered a setback during a training session in Perth earlier this week. Following a scan, the team management decided to send him back to the United Kingdom on Saturday for further specialist assessment.
"Jacob Bethell has been ruled out of the white-ball tour of Australia following a scan on his right knee," the England spokesperson confirmed.
"Bethell suffered a setback in his return from the injury during a training session in Perth earlier this week. With a busy winter ahead, it was decided that he will return to the UK on Saturday before seeing a specialist."
Major Blow for England Ahead of Australia Tour
Bethell's absence is a significant setback for England, particularly after he had begun establishing himself as an important member of their ODI setup.
His last international appearance came against India at Lord's in July, where he produced an impressive all-round performance, scoring 91 runs and taking one wicket for 49 runs in his 10 overs. He was also named Player of the Match.
The youngster had opened the batting during the India series, but Tom Banton has since strengthened his position at the top of the order. Banton has scored 394 runs at an average of 56.28 since his promotion, including one century and four half-centuries.
Bethell's absence will provide Banton with another opportunity to cement his place as Ben Duckett's opening partner during the Australia tour.
South Africa Test Series Now in Doubt
The injury setback has also raised questions about Bethell's availability for England's upcoming three-match Test series against South Africa, which begins on December 17 at the Wanderers Stadium in Johannesburg.
Bethell was included in England's 15-member squad for the series and is competing with Emilio Gay, Jordan Cox and Dan Lawrence for a place in the top six.
There had also been suggestions that he could be considered as an opening option in Test cricket for the first time. However, his participation will depend on how quickly he recovers from the latest setback.
Former England captain Joe Root expressed disappointment over the youngster's situation and hoped that the injury would not keep him out of action for much longer.
"It's disappointing for him. I know how hard he works, and I know everything he's done to get himself right, and hopefully it's not too serious and he's not out for too long," Root told the BBC.
James Coles Called Up as Replacement
Meanwhile, England have called up Sussex all-rounder James Coles as Bethell's replacement for the Australia tour.
Coles was originally scheduled to join the squad for the five-match T20I series later this month but will now travel to Perth earlier after leaving the England Lions' tour of St Kitts.
The 22-year-old, who also bowls left-arm orthodox spin, will provide England with an additional all-round option.
England have also added Hampshire fast bowler Eddie Jack to their ODI squad following Josh Tongue's early departure due to an injured big toe.
Jack recently impressed for England Lions, claiming five wickets for 42 runs in their comprehensive 266-run victory over West Indies A.
Both Coles and Jack are expected to remain with the England squad for the T20I series.
Bethell will now focus on his rehabilitation and specialist assessment in the UK, with his availability for the crucial South Africa Test series remaining uncertain.
