Losing a guy like Patty is massive for a team
Wallaby midfielder Pat McCabe will return to Australia this week after it was confirmed that he had suffered a neck fracture.
McCaw, who missed the Wallabies' 20-14 win over England at the weekend, suffered the neck injury in the 6-33 loss to France the week before.
The Canberra Times reported that scans revealed he had suffered a C1 fracture in his neck.
The predicted recovery time frame will keep McCabe out of training until mid-February and he will then need time to regain fitness and strength - meaning he is likely to miss a substantial portion of the Super Rugby season.
The Brumbies will have to wait until McCabe arrives in Canberra this week and meets with club medical staff before knowing how long the 24-year-old will be missing for.
"We've got experience now and we know we've got guys who can slot into that position," Brumbies backs coach Stephen Larkham told the Canberra Times.
"But losing a guy like Patty is massive for a team. He's great with leadership on and off the field and just the way he plays is outstanding.
"He's certainly going to be missed, but it will give someone else a chance to step up and have a crack at inside-centre."
McCabe was one of the most consistent players in the Brumbies' backline last season and cemented his place in Robbie Deans's side.
McCabe also missed the start of last Super Rugby season after having a shoulder reconstruction following the World Cup.
While he is versatile, Larkham had planned to use McCabe mainly as a centre next year.