Craig Bellamy has been diagnosed with an unspecified neurodegenerative disorder, but will remain as coach of Melbourne Storm in the immediate future.
The club issued a statement 24 hours out from Melbourne's NRL clash with the Dolphins in Brisbane after the 66-year-old Bellamy underwent a series of recent tests.
"Over recent weeks, in consultation with specialists, Craig has undergone a series of medical tests and has since been diagnosed with a form of neurodegenerative disorder," the club said in a statement on Thursday.
"He is receiving the best possible medical treatment and has been advised by specialists that his diagnosis will not have an impact on his ability to coach the team in the immediate future."
In February, Bellamy signed a new contract through until the end of the 2028 season.
He has coached 614 NRL games, only behind Wayne Bennett and the retired Tim Sheens.
The Storm are enduring a horror season, dropping six successive matches for the first time since Bellamy took over as coach in 2003.
A seventh straight loss in Brisbane will equal the all-time club record.
Despite the recent woes, Melbourne chairman Matt Tripp said he believed Bellamy was still up to coaching at NRL level.
"Despite our recent results, I firmly believe Craig is still coaching at an elite level and I have no doubt he is the right person to drive the club forward," Tripp said in the statement.
"Craig has the full support of the board, players, coaches and staff to continue leading the Club as he has done for the last 24 seasons."
Bellamy was at Storm training in Melbourne on Thursday and showed no signs of ill health.
Melbourne have had a run of upsetting health and injury issues.
As well as Bellamy, Eli Katoa underwent surgery to stop a brain bleed last November after a series of head knocks while fellow Storm forward Tui Kamikamica is currently sidelined after suffering a stroke last month.
He also underwent brain and heart surgery.