Warburton, who captained Wales to the Grand Slam in this year’s Six Nations, has not played a game since suffering nerve damage to his shoulder in his side’s win against France at the start of last month.
And with the tour Down Under fast approaching the Cardiff Blues flanker knows he faces a race against time to prove his fitness.
“I have to wait a bit longer,” said Warburton, who saw a specialist in London on Tuesday.
“It’s very hard to put a time scale on a nerve [injury]. They told me that at the start to be honest.
“He [the specialist] did say ‘I can’t be 100 per cent certain because I’ve seen these things drag on and I’ve seen the recover very quickly’, so wait and see really.”
“I’ve been able to do some quite extensive rehab and the physios at Wales and the Blues have been fantastic over the last five weeks. Hopefully I’ll come back pretty fresh.”
Warburton is not the only injury concern for Wales who will have to be without head coach Warren Gatland after a fall suffered at his home in his native New Zealand.
But it is not just the coaching staff that have caught the injury bug as caretaker head coach Rob Howley faces the unenviable task of picking a squad to go to Australia that could be without the likes of Warburton, Jamie Roberts, Scott Williams and Jonathan Davies.
But Warburton is convinced there is enough quality in the Wales set-up to cope with any absentees when the tour gets underway.
“There will be opportunities to try out new guys on this tour,” he said. “But at the end of the day it is not a development tour – we’re going down there to win a Test series and it’s going to be very competitive.
“Hopefully everybody can come through these regional games without niggles and we can take a full strength squad. I think we’ve got a great chance of winning down there.”
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