In the midst of the turmoil, Faumuina tore his right calf muscle and is likely to miss the next six weeks of the tournament.
That crucial stretch starts on Saturday when the Blues travel to Mt Maunganui to play the Chiefs before they square off against the Highlanders and Hurricanes in their section.
Repair work started yesterday as the squad held their debrief in Sydney where they were taken through video replays of their latest sloppy defeat.
Warm fuzzies from opening wins against the Hurricanes and Crusaders have been balanced by successive losses to the Bulls and Waratahs as the Blues search for the rhythm to get their campaign back on track.
Kirwan was most alarmed by the mistake rate and staff detailed at least 30 gaffes involving turnovers, missed tackles and penalty concessions. A trickle at halftime became a flow by the time referee Francisco Pastrana called time.
The Blues were exasperated by his rulings, especially at the ruck.
"We did not know what was going on there so at halftime we told our guys to clean it up, hang on to the ball, be steady and play field position," Kirwan said.
"We were average up until halftime yet we led 24-10.
"But then we couldn't string three phases together, we made handling errors and I don't know why. We lost the football game.
"We did not have the ability to recognise the winning moments."
The instructions were to be more disciplined and collect points from Chris Noakes' boot.
While some like five-eighths Noakes, flankers Luke Braid and Steven Luatua and hooker James Parsons stood up, there was a leaden look about many of their teammates.
Captain Ali Williams was subbed after 50 minutes, while performance fluctuated from senior backs Piri Weepu and Rene Ranger.
The Blues' advantage ebbed way as Waratahs five-eighths Bernard Foley converted his own try then two penalties in the last quarter, including the final act of the match, to filch victory.
When Foley missed a late dropped goal attempt, the Blues should have clung on for the draw but they infringed at a ruck and Foley drilled the winning penalty.
"The errors were like a disease," said Kirwan.
"We did not have the maturity to know what to do and how to stop it. You cannot win a football game like that with our numbers of errors and indiscipline.
"We let ourselves down and now we have to show some steel against the Chiefs this weekend.
"Our conference games have taken on even more importance."
