Australia, already sweating over the fitness of key line-out forwards Nathan Sharpe and Dan Vickerman ahead of their Tri-Nations clash against South Africa in Perth on Saturday, were given another injury scare on Tuesday when back-up lock James Horwill suffered a training ground injury.

Horwill was forced to sit out the latter half of a training session after copping a heavy knock to the sternum, while Vickerman also failed to complete the session as he continues his return from ankle surgery.

Wallaby coach Robbie Deans will be a bit happier after Sharpe appeared to have recovered from the groin injury that kept him out of the 40-10 second Test victory over France in Brisbane a fortnight ago.

Vickerman, who was sidelined for Australia's Test wins over Ireland and France after undergoing ankle surgery following the Super 14 season, made a successful return to club rugby over the weekend.

But the 29-year-old iced his right ankle for 20 minutes and was limping noticeably afterwards.

In better news inside centre Berrick Barnes, who injured his shoulder against France, got through the physical session unscathed.

"It's good. I got through that contact session fine and as you saw it was pretty physical," Barnes told AAP.

"I'll be having plenty more [hits] come Saturday night so we know what to expect."

365