Hooper was expected to emerge from two weeks in quarantine to make his eagerly-awaited first appearance for Toyota Verblitz on Saturday alongside former All Blacks skipper Kieran Read and 2019 Springboks World Cup winner Willie le Roux.

The trio were set to go head-to-head with the likes of New Zealand superstar Beauden Barrett and ex-Wallabies duo Samu Kerevi and Sean McMahon, who are now playing for Suntory Sungoliath.

Former Melbourne Storm NRL premiership winner Will Chambers and Queensland lock Harry Hockings are also on Suntory's books.

But the Japan Rugby Football Union on Tuesday said two of this weekend's eight scheduled opening-round games, including Toyota versus Suntory in Aichi Prefecture, had been cancelled after three of the teams involved confirmed positive coronavirus cases.

The JRFU said a total of 44 players and staff tested positive for the virus, including 24 from Canon Eagles, 13 from Toyota and seven from Suntory.

"The Top League has created COVID-19 protocols and procedures together with the teams, but there's still so much that's unknown about the virus and we feel threatened," Top League chairman Osamu Ota said in a statement.

"Fortunately none of the players are seriously ill but I pray for their quick recovery."

The other game that has been cancelled is Canon's opener against Ricoh Black Rams scheduled for Sunday at Tokyo's Komazawa Stadium.

Neither games will be rescheduled. Under league policy, they will be considered draws, with each team getting two points.

This year in the first stage of Japan's top-tier domestic rugby union competition, the 16 Top League teams will be divided into two conferences to determine their seedings for the second stage.

A total of 20 teams, including four from the Top Challenge League, will be split into four groups of five teams in the second stage.

The top two teams of each group proceed to the playoffs.

Last year, the Top League season was cancelled in March because of the pandemic.

Former Wallabies coach Robbie Deans' Panasonic Wild Knights were unbeaten when the season was abandoned and dearly hopes the competition will proceed with fewer disruptions in 2021.

"That was a source of frustration for us. We were sitting at the top of the table - six games and six bonus points," Deans told AAP on Tuesday.

"So (we were) humming and they just pulled the rug out, which never excites the players. They like to play.

"So hopefully we get some rugby because you can only maintain your interest in training for so long."

Australian Associated Press