The Brumbies could be without the services of prop Scott Sio and fly-half Matt Toomua for four to six weeks after they were injured in Friday's loss to the Blues in Auckland.
Sio damaged the medial ligament in his knee and Toomua will have a scan on a potential ankle syndesmosis (high ankle sprain).
These injuries will be huge setbacks to the Brumbies who are currently at the top of the Australian Conference.
“We got a couple of injuries in the game which is not ideal, but it will give other guys an opportunity to get their chance,” Brumbies captain Stephen Moore told the Australian.
“We are not sure exactly how long we will be without them. It depends on how bad the damage is. We are hoping it’s on the shorter side as opposed to a long term thing. We just don’t know yet.”
JP Smith is set to come in for Sio in the starting line-up when the Brumbies face the Melbourne Rebels in Canberra on Friday while regular inside centre Christian Lealiifano is expected to move to fly-half as Toomua's replacement.
“When you lose your playmaker it’s going to be a blow, but Christian has played there a lot and he did a good job when he stepped in there,” added Moore.
“We are well served if that’s the way we have to go.
“JP did a really good job when Scotty went off. His workrate was fantastic.”