The Blues have had their disappointing loss to the Waratahs complicated by a serious calf injury to All Blacks prop Charlie Faumuina.
The Blues confirmed today that Faumuina suffered a grade two calf strain on his right leg during yesterday's 27-30 loss in Sydney.
He is likely to be out of action for between four to six weeks.
Faumuina, who is on crutches, will have an ultrasound scan tomorrow to assess the full extent of the injury.
The propping department isn't an area of strength for the Blues following the offseason departure of Tony Woodcock.
Faumnina was their senior pro and coach Sir John Kirwan is now left with a vulnerable area in his forwards.
The Blues, who have lost consecutive matches to the Bulls and Waratahs after opening with two wins, face a huge assignment against the Chiefs over Easter.
They play the Chiefs in Mt Maunganui on Saturday night.
The New Zealand conference tightened last weekend. The Chiefs remain top with the improving Crusaders slipping past the Blues into second on points differential.
The Hurricanes are in the mix too, with the winless Highlanders rooted to the bottom of the table.
The Highlanders host the Reds on Friday with the Hurricanes at home to the struggling Kings on Saturday and the Crusaders facing a tough examination from the Stormers in Cape Town on Sunday morning (NZT).
- Fairfax Media
Which 2015 NZ Super Rugby team looks best?