DARWIN, AUSTRALIA - JULY 19: Lleyton Hewitt of Australia celebrates during the reverse singles match between Lleyton Hewitt of Australia and Aleksandr Nedovyesov of Kazakhstan during day three of the Davis Cup World Group quarterfinal tie between Australia and Kazakhstan at Marrara Sporting Complex on July 19, 2015 in Darwin, Australia. (Photo by Scott Barbour/Getty Images)

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.

“He’s enjoyed the hitting. We thought he’d retired, he’s been hitting more than these guys.

“It’s probably the first time that a captain has had to get out and prepare as if he may play.

“Look, he’s a great team man and he’ll do whatever he needs to do - whether that’s playing or sitting on the side.

“We don’t expect he’ll play but we’ll have to wait and see the next couple of days.”

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

“Nick’s arrived today and, as far as we know, he’s OK,” Stoltenberg said.

“He’s had a bit of a virus. He’s taken a couple of extra days back home.

“We’ll see him here soon but we have all expectation he’ll be fine.

“He’ll hit today.”