The 28-year-old plays for the Brumbies and has 19 Tests for Australia
Australian rugby player Christian Lealiifano has been diagnosed with leukaemia and is undergoing treatment in hospital.
The Brumbies player was diagnosed following a brief illness and coaches, staff and players were informed before the club released a statement.
"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," it read.
"Everyone knows that Christian is an amazing young man, an important member of this team and of the Canberra community.
"Our thoughts and prayers are with Christian and his family at this time."
The well wishes and prayers have also come rushing in from online including friends of his from his sporting past and present.
Just finished marching in Opening Ceremony & received the news on @CLealiifano. My night doesn't feel so special anymore. Get well Bruz...— Andy Friend (@andyfriend2011) August 6, 2016
Really tough 24 hours trying to come to terms with news about Christian. One of the most respected and loved players I've played alongside.— David Pocock (@pocockdavid) August 6, 2016
The player has played in 19 tests for Australia and just gave birth to his first son, Jeremih, in June with his partner Luga.