But Wallabies coach Robbie Deans is optimistic his star back row man will be fit to return for the Millennium Stadium showdown with the Grand Slam champions in Australia's 14th and final fixture of the year.
Deans told AAP that Pocock, who had only just recovered from knee ligament damage, had been running this week.
"Hopefully he'll be available to us next week. We're just being precautionary and I guess we've got the luxury of being able to do that," said Deans
"We've got Michael Hooper and Liam Gill and they're both fully fit and so we see no reason to push David. I suspect if pressed he could have played this week, but if he's not 100 per cent you won't see him in Cardiff."
Pocock led the Wallabies to a 3-0 test series victory over Wales on home soil in the summer and will no doubt be keen to sign off the season with one final game - and try to make it six straight wins over Wales for the men in gold in 13 months.