Northampton Saints and former Wallaby centre Rob Horne forced to retire following nerve damage.
Horne was forced from the field of Saints and Leicester Tigers' Premiership game last weekend following an attempted tackle on Sione Kalamafoni within the first minute.
The 34-times-capped Australian international suffered career-ending nerve damage in an attempted tackle on Tongan number eight and was taken immediately to the hospital to be assessed.
The 28-year-old joined the Saints from the Waratahs in 2017 and was captaining his new side for the first time at Welford Road before being knocked unconscious.
Horne played in two Rugby World Cup campaigns for the Wallabies and featured against the British and Irish Lions in 2013.
"After undergoing tests, leading neurological consultants from the Royal National Orthopaedic Hospital (Stanmore) confirmed that Horne has suffered career nerve damage to his right arm," said a Northampton statement.
Interim Saints Head Coach Alan Dickins commented: "This is absolutely tragic news, and has been devastating for every member of the squad and staff here.
"All our thoughts are of course with Rob and his family at this time. Rob is not only an exceptional rugby player, but he's an exceptional man."
An intelligent attacker and defensive lynchpin both individually and as a leader, the retirement of Rob Horne is a sad day for not only his loved ones, but the sport as a whole.