Melbourne VIC, Australia, 1 March 2016 | AAP

A virus is keeping Nick Kyrgios away from Kooyong as Australia prepares to face the United States in the Davis Cup this weekend.

Kyrgios, Australia’s No.2 singles player, was under an injury cloud leading into the first-round tie after playing with a back and hip injury in ATP tour events in Marseille and Dubai.

Australian team captain Lleyton Hewitt said Kyrgios had been ordered to recover fully away from the team as he strives to be completely fit.

“At the moment he’s taking it easy and trying to get over it 100 per cent,” Hewitt said.

“I didn’t want him around the boys if he’s a bit infectious. It’s precaution more than anything.

“The back and hip don’t seem to be a problem which is very good good news.

“He’s played a lot of matches and both he and Bernie (Tomic) are confident coming in with their ball-striking. Come match day I’m backing both those boys.”

Lead singles player Tomic hit the courts on Tuesday after a tricky transit from Mexican resort city Acapulco.

Tomic reached the final of the tour event there but needed painkillers to do so after developing his own wrist ailment.

He went straight to Kooyong within a few hours of touching down and said while he might be short of full fitness for the tie, he would compete well.

“I finished the final and had to fly five or six hours after that,” he said.

“It was very tough to get here but the hit today, it was good to get on the court and now on grass, I have to try and get ready as much as I can.

“I’ve had (the wrist injury) since I played Murray in the Australian Open. It’s OK … I haven’t pulled out anywhere. I’ve pushed through it.

“It’s tough to say if I’ll be at 100 per cent but there’s not going to be a lot of rallies … it’s going to be a lot of quick points.

“I’m very happy the way I’m playing and I think I’ll be very ready for sure on Friday.”

USA captain Jim Courier said he was expecting to face a full-strength Australian team despite Kyrgios’ initial absence from Kooyong.