Lleyton Hewitt plays down Davis Cup comeback reports

Lleyton Hewitt has played down reports he could return to the court for Australia's Davis Cup tie against the United States after Nick Kyrgios was ruled out of the tie.

The 35-year-old team captain called time on his playing career at the Australian Open six weeks ago but made himself available for Davis Cup duty on Thursday after Kyrgios pulled out due to a virus.

However, Hewitt said there was "zero" chance he would play at Melbourne's Kooyong Lawn Tennis Club with Sam Groth named to play both the opening and reverse singles against John Isner and Jack Sock in place of Kyrgios at the draw ceremony on Thursday.

Groth and John Peers will play the Bryan brothers in Saturday's doubles on the specially prepared grass court at the former Australian Open venue.

Nominations for the doubles and the reverse singles on Sunday can still be changed, but former world No 1 Hewitt, who was busy on the practice court this week, suggested he would only play a part if there was no-one left standing.

"I've been around enough Davis Cup ties now to know you've got to have back-ups and plans in place," said Hewitt, a Davis Cup winner in 1999 and 2003.

"I'm hitting the ball well and we've got as good a team as we can field going in and I'm confident we can still win."

World No 77 Groth leads off the Friday singles against world No 11 John Isner, a battle between two of the game's biggest servers.

Tomic, ranked 20th, then meets world No 23 Sock, who has beaten him in both their previous matches.

"I'm playing very well and I'm playing on a surface that's my favourite," said Tomic, runner-up at Acapulco on Saturday.

"I love this grass. It's not too quick and I move well on it so it suits my tennis and it's going to suit Grothy as well so it favours us."