Wallabies back Christian Lealiifano has been diagnosed with Leukaemia.
The Brumbies co-captain, who was not named in the Wallabies squad on Friday is currently in hospital receiving treatment.
The Brumbies said, in a statement, that after a brief illness, investigations revealed the disease.
“At the moment it’s just a matter of ensuring Christian receives the best care and support he can at this time,” Brumbies chief Phil Thomson said.
“He is one of the most respected players within this group and this news has come as a huge shock to all of our players, coaches and staff.
“Everyone knows that Christian is an amazing young man, an important member of this team and of the Canberra community.”
ARU boss Bill Pulver, who is in Rio to watch the Aussie Sevens team at the Olympics also gave Lealiifano his full support.
“We were shocked to receive the news of Christian’s diagnosis yesterday and our thoughts are firmly with him as he begins his treatment,”Pulver said via a statement.
“Anyone who has ever had any involvement with Christian knows he is an outstanding young man, as well as being an exceptionally talented rugby player, and the ARU will do whatever it can to support Christian and his family now and throughout his treatment.”