The Sunwolves will not play in the Australia-based Super Rugby competition this year due to the coronavirus pandemic.
Like New Zealand, Australia is planning to hold a domestic tournament, beginning on July 3, after Super Rugby was stopped in March due to COVID-19.
While the Force are returning to play in the competition, Rugby Australia (RA) announced on Monday the Japan-based Sunwolves would not participate.
Travel restrictions in Australia mean the Sunwolves would be forced into a 14-day quarantine period on arrival if they were allowed to enter, hindering their preparation.
"There are significant challenges facing the Sunwolves' participation in this modified competition model which Rugby Australia, SANZAAR and the Sunwolves have been attempting to work through," RA interim chief executive Rob Clarke said.
"However, the reality is, given the timeframe available the team's preparation for the competition would be severely compromised.
"All parties agree that despite our collective efforts and desire to see the Sunwolves take part in the competition, under the current circumstances their participation will not be feasible. While unfortunate, this decision delivers the certainty that all stakeholders require at this point in time.
"We all agree that this is not the way we wanted or believed that the 2020 Super Rugby season would play out when it kicked off back in late January, the impact of COVID-19 has been unprecedented and unforeseen.
"On behalf of Rugby Australia, our SANZAAR partners and the rugby community I pass on our thanks to the Sunwolves and we look forward to continuing to build on the links between Australia and Japan on and off the rugby field."
The Sunwolves had lost four of their opening five games of the season before the campaign was suspended.
It ends their brief stay in Super Rugby after it was announced last year that the 2020 season would be their last.
Australia has seen more than 7,100 cases of coronavirus and 103 deaths, while Japan's death toll is nearing 900.