Nick Kyrgios has finally arrived in Melbourne for this week’s Davis Cup tie against the United States, with Sam Groth placed on standby as the world No.27 battles a mystery virus.

Australian coach Jason Stoltenberg confirmed Kyrgios would hit with his teammates on the Kooyong grass on Wednesday afternoon.

Groth – who will partner John Peers in Saturday’s doubles rubber – says he is ready to step in should either Kyrgios (back/hip/virus) or Bernard Tomic (wrist) be forced to pull out of Friday’s opening singles matches.