Leeds Rhinos' shutdown of their training ground is to be extended for a further five days after four more positive Covid-19 cases at the club.
The Rhinos closed their Kirkstall Road training ground last week after six players and a member of staff were said to have contracted the virus.
Huddersfield Giants were also forced to close their facility last week.
"The rationale is to ensure any trace of the virus is eradicated prior to return," a Leeds statement said.
"It is hoped that with the additional stand-down period being observed all cases will be picked up during this period and a return following gives a clear restart.
"This process will remain under review depending on the test results over the next five days."
The Super League club say they have worked alongside the Rugby Football League's Multiple Case Group and that members of playing and coaching staff will continue to be tested.
A further round of testing will take place on Friday, 10 days since the training ground was initially shut down.
Super League players were allowed to resume training earlier this month, with a target date of 25 March for the start of the new season.
"I am pleased to say all those who have tested positive are either asymptomatic or suffering mild symptoms and they continue to receive the full support of the club," Leeds director of rugby Kevin Sinfield said.
"With us testing every day, it enables us to monitor the whole group and we are confident we are moving in the right direction to return to training as soon as it is safe to do so."