Wallaby coach Robbie Deans has been forced to call up uncapped Brumbies skipper Ben Mowen to act as cover for number eight Ben McCalman, having already lost skipper James Horwill and utility back James O'Connor, while Kurtley Beale is fighting to be fit after shoulder surgery.
McCalman has been suffering from a nerve problem in his shoulder for most of the season and was forced to sit out Western Force's Super 15 tour of South Africa at the start of May. He had missed three games earlier in the season because of the same problem.
Deans is due to announce his team to play Scotland in Newcastle on Tuesday night on Sunday.
That team is expected to be led by flanker David Pocock in Horwill's absence and feature Queensland Reds New Zealand-born outside half Mike Harris.
Deans' biggest headache is whether or not to risk sending the inspirational Quade Cooper back into the Test arena against Wales on Saturday after only 120 minutes of action since the knee operation he needed after suffering an injury in the World Cup bronze final against the same opponents.
The 24-year-old McCalman has played in the three wins by Australia over Wales and has established himself as the first-choice number eight. He now has 21 caps since making his Test debut in 2010.
Brumbies captain Mowen was looking forward to leading his side against Wales in Canberra in the one non-Test game the tourists will play Down Under, but is now contemplating winning his first cap against them instead.
He led the side to a 27-19 win over the Melbourne Rebels in Friday night's Super 15 clash in Victoria, which maintained the Brumbies' lead at the top of the Australian Conference standings in the competition.
The uncapped 27-year-old previously represented Australia at schools and under-21 levels, as well as featuring for the Australian Sevens side. McCalman is set to remain in the Wallaby camp in the short term to work with the Australian medical staff on his rehabilitation from the injury.
Also on the sidelines at present is another of the Wallabies' leading locks, former Cambridge University skipper Dan Vickerman.
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