"We’re still waiting on him," Wales assistant coach Neil Jenkins told reporters on Monday. "Everyone saw it, it doesn’t look great. He’s going to struggle for the rest of this autumn but hopefully it’s not too serious.
"I’m not saying he’s out but we just need to see where he’s at. He was outstanding for the (British & Irish) Lions and last year for us. He’s a world class player."
The 31-year-old Roberts, who has 93 caps, was left out of the initial squad after captaining Wales to victories over Tonga and Samoa on this year's tour.
"He’s an outstanding player. He was unlucky to miss out initially. He’s been part of the set-up for a very long time and he’ll just fit in. He’s a fantastic player and person," Jenkins said.
Prop Scott Andrews has also joined the squad as cover for Samson Lee, who missed the Wallabies game with an Achilles injury.
Wales are preparing to face Georgia in Cardiff on Saturday.
(Reporting by Hardik Vyas in Bengaluru and Nick Said in Cape Town, editing by Ed Osmond)
