Canberra - Star fullback Mark Gerrard has been ruled out of the Brumbies' crucial Super 14 clash with the Blues in Canberra on Saturday after aggravating a hamstring injury.
The loss of Gerrard will see fellow Wallaby Adam Ashley-Cooper move to fullback while Francis Fainifo returns to the starting line-up to take up the right wing position.
Wallabies captain Stirling Mortlock will remain on the left wing for the clash with the Blues.
Mortlock is just eight points shy of the Super rugby all-time point scoring record of 990 points held by Crusaders five-eighth Andrew Mehrtens and could easily break it before his home crowd at Canberra Stadium.
The Brumbies pack regains tighthead prop Guy Shepherdson who returns from a two week suspension.
Coming off a 52-13 win over the Reds last weekend, the Brumbies can move into the top four with a win over the Blues if other results go their way.
Brumbies coach Andy Friend said Saturday's match will be a critical encounter for both the sides as they vie for a semi-finals berth.
"Last weekend's performance against the Reds was unquestionably an improved one from the week before but we haven't dwelled too much on it," Friend said.
"We've been quick to move our focus onto the Blues, who, like us, will be playing to keep their season alive."
"Both sides have shown a desire to play an open brand of rugby but given that they've scored seven bonus-point wins, we'll also need to ensure that our defence is in check as it was against the Reds."
The Brumbies are yet to name their bench due to a number of players remaining in doubt through injury.
Brumbies: Adam Ashley-Cooper, Francis Fainifo, Tyrone Smith, Gene Fairbanks, Stirling Mortlock, Matt Toomua, Patrick Phibbs, Stephen Hoiles (capt), George Smith, Mitchell Chapman, Peter Kimlin, Ben Hand, Guy Shepherdson, Stephen Moore, Ben Alexander. Res: TBA.