It is the second dislocated digit suffered by Agar in less than two years. He sufferd a similar injury to his right little finger during Australia's tour of India in September 2017
Ashton Agar has been ruled out of the rest of the Big Bash season through injury.
The allrounder sustained a dislocated right index finger during training with Perth Scorchers and will require surgery to fix the problem.
It is the second dislocated digit suffered by Agar in less than two years. He sufferd a similar injury to his right little finger during Australia's tour of India in September 2017.
"Ash Agar unfortunately suffered a fracture dislocation to his right index finger whilst fielding at training yesterday," Nick Jones, Scorchers' sports medicine manager, said.

Ashton Agar is out of the Big Bash through injury
"Ash sustained an intra-articular fracture that will require surgical repair. We expect that Ash will undergo surgery in the coming days, and as a result will be unavailable for the remainder of the BBL."
The issue comes at a bad time for Australia, with Agar in contention for a place in the 50-over squad for games against India and Pakistan in February and March, which will act as warm-ups for the World Cup later this year.
Agar, who claimed just five Big Bash wickets in 2018-19, had been dropped from the side for the current series against India.
BIG BASH: Sydney Thunder lodge formal protest over no result
Subscribe to The Cricketer for exclusive content every day: The inside track on England's Test tour with George Dobell in Pakistan, award-winning analysis, breaking news and interviews and the only place for in-depth county coverage all year round. Plus: An ad-free app experience at your fingertips. Subscribe to thecricketer.com today for just £1.