The Australian rugby coach Robbie Deans looks set to gamble with a forwards-heavy 6-2 bench split to beef up his back-row for Saturday night's test series decider against the British and Irish Lions.
Versatile forward Ben McCalman has been confirmed as a shock inclusion for the Wallabies, while veteran George Smith will start at No.7 and bump Michael Hooper to the bench at Sydney's ANZ Stadium.
But only two backline reserves - halfback Nick Phipps and uncapped fullback Jesse Mogg - are expected to be picked on the bench when Deans names his side today, leaving the midfield particularly exposed and vulnerable if an injury occurs.
Centre Adam Ashley-Cooper was in doubt for the second test with a shoulder problem and also ended the series equaliser with concerns over his knee.
Ashley-Cooper is set to start at No.13 but there is no obvious back-up for him if he's sidelined.
The risky move may have come as Deans was unhappy with the Wallabies efficiency at the breakdown in Melbourne and having Smith start and Hooper and McCalman to be injected in the second half will pressure the tiring Lions.
Smith's return for what will be his 111th and most likely last test match is set to come at the expense of young openside Liam Gill.