Speculation is mounting that Lleyton Hewitt could take to the court for Australia in the Davis Cup this weekend due to the Aussies' mounting injury toll.

Nick Kygrios failed to train with the team yesterday as he battles a back problem that he sustained in Dubai last week, as well as a virus.

Australian coach Jason Stoltenberg admitted Hewitt could come out of retirement for the tie if Kyrgios is not fit enough to play.

โ€œHe's enjoyed the hitting. We thought he'd retired, he's been hitting more than these guys.

โ€œIt's probably the first time that a captain has had to get out and prepare as if he may play.

โ€œLook, he's a great team man and he'll do whatever he needs to do - whether that's playing or sitting on the side.

โ€œWe don't expect he'll play but we'll have to wait and see the next couple of days.โ€

However, Stoltenberg said he expected Kyrgios to be able to play.

โ€œNick's arrived today and, as far as we know, he's OK,โ€ Stoltenberg said.

โ€œHe's had a bit of a virus. He's taken a couple of extra days back home.

โ€œWe'll see him here soon but we have all expectation he'll be fine.

โ€œHe'll hit today.โ€