Nick Kyrgios of Australia plays a backhand in his singles match against Aleksandr Nedovyesov of Kazakhstan during day one of the Davis Cup World Group quarterfinal tie between Australia and Kazakhstan at Marrara Sporting Complex on July 17, 2015 in Darwin, Australia. (Photo by Scott Barbour/Getty Images)

Lleyton Hewitt has announced Australia's Davis Cup squad to face Slovakia in the World Group Play-off tie in Sydney later this month.

The squad features Nick Kyrgios, Bernard Tomic, John Millman, James Duckworth, John Peers and Sam Groth.

The team will then be cut to four players just prior to the tie.

“This is a must win for us to secure our spot in the World Group next year and I know all the boys are fired up and ready to go out and get the win for Australia,” Hewitt said.

“Bernard and Nick are both firmly established in the top 20, Sam has proven himself as a Davis Cup player over the past two years and to be able to bring in John as a doubles specialist is a great advantage.

Australian team captain Lleyton Hewitt cheers on Bernard Tomic of Australia as he plays against John Isner of the US during the men's reverse singles match at the World Group first round Davis Cup tennis tournament at Kooyong in Melbourne on March 6, 2016. / AFP / Paul Crock / --IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE-- (Photo credit should read PAUL CROCK/AFP/Getty Images)
Australian team captain Lleyton Hewitt cheers on Bernard Tomic of Australia as he plays against John Isner of the US during the men's reverse singles match at the World Group first round Davis Cup tennis tournament at Kooyong in Melbourne on March 6, 2016. PAUL CROCK/AFP/Getty Images.

“I'm also really pleased to bring James Duckworth and John Millman into the squad. They both put in terrific performances at the US Open and give us a lot of flexibility.

“We have never played Slovakia before but they have some dangerous players in Martin Klizan and Lukas Lacko and we'll have to play our best tennis to get the win.

“Playing for our spot in the World Group in an arena named after one of Australia's great Davis Cup players, Ken Rosewall, will certainly provide plenty of inspiration.”

The tie will be played from September 16-18, with the winner set to advance to the 2017 World Group.