Waratahs captain Michael Hooper has said they were to eager at times and it cost them dearly, in their 32-15 defeat to the Brumbies in Canberra on Friday.
The visitors conceded four penalties in as many minutes.
"It wasn't intentional. We wanted to start really hard and get up and in their faces and probably a bit eager there. [It] led to penalties and [we] really put ourselves under pressure for that first 30 minutes and took a bit of gas out the tank," Hooper said to the Sydney Morning Herald.
The 2014 champions have been hit with injuries to three players – Tatafu Polota-Nau fractured his wrist, outside centre Rob Horne injured his knee and replacement full-back Bruce Hegarty will need treatment to an ACL injury.
The injury to Hegarty could see him out of action for weeks.
"Tough night, but injuries are all part of the season but that's why you have a squad," coach Daryl Gibson said.
Two yellow cards – Will Skelton and Dean Mumm – certainly did not help the come-back for Gibson's men.
"Those yellow cards clearly didn't help," said Gibson.
"Defending with 14 and to absorb all the Brumbies' pressure and go into the break at 8-8 (was a good effort).
"Plenty to work on…we want to be more consistent with our play and accuracy."
Gibson eluded to the quality of rugby displayed by the Brumbies, and has said the Australian conference leaders are setting the pace.
"It's certainly not terminal. What it does is give us clear direction on what we need to improve on. Currently the Brumbies are setting the standard and now we know where that standard is."
Waratahs have a bye next week and will face defending champions, the Highlanders at Allianz Park in round four.