Australia flanker David Pocock is facing nine months on the sidelines following knee reconstruction surgery.
The 24-year-old had the operation on his left knee after he tore the anterior cruciate ligament while playing for Brumbies against the Waratahs. Pocock had fallen badly after being tackled by Adam Ashley-Cooper.
"I'm pleased to have the surgery out of the way," Pocock said in a statement.
"Now I need to rest up and get myself ready to start the rehabilitation process.
"The key thing is that I'm patient and don't try to rush back. If that means season over, in terms of playing any more rugby this year, then so be it. Once I get into the rehabilitation, we'll see how it goes."
Pocock is now unlikely to return to action until the 2014 Super Rugby season - meaning he will miss the three-Test series against the British and Irish Lions, the Rugby Championship and the autumn tour.