Robbie Deans was left sweating over injuries to Tatafu Polota-Nau, George Smith and Pat McCabe after the Waratahs beat the Brumbies.
Polota-Nau's involvement in the Test series against the British and Irish Lions is now majorly in doubt after the Waratahs hooker fractured his forearm in the first-half.
Rumoured to be out for somewhere between four to six weeks, the Test series is now just over a month away.
Smith meanwhile looked to have suffered a potentially serious knee injury after leaving the field during the second half.
With his knee heavily iced, the initial fears are that Smith has damaged his medial ligament and could be out for a period of up to eight weeks.
Possessing 110 caps, Smith was seen by many as a certainty to start for the Wallabies following the loss of David Pocock earlier in the season. Now youngsters Liam Gill and Michael Hooper appear more likely to fill the openside role.
Elsewhere centre McCabe was forced off after just 32 minutes with a knee injury, the latest in a long-run for the Brumbies centre who damaged his neck and hamstring last season.
"I'm not going to say [Smith] is fine, he's got a bang on the knee and there's concern," said Brumbies boss Jake White to the Sydney Morning Herald.
"Doctors don't want to tell you the worst-case scenario, but at this point in time it looks like it might be his medial ligament.
"But if it's a 6-8 week injury it means he won't be in the Lions series. We'll just wait to see how it pans out once he's had a scan."