DOUBLES specialist John Peers could prove to be the key for Australia in this weekend's Davis Cup semi-final against Belgium.
But just who will partner the man ranked No.1 in the world, with Finland's Henri Kontinen, in Saturday's crucial doubles rubber in Brussels is unsure, with captain Lleyton Hewitt weighing up his options.
Hewitt was set to name the pairing overnight, with Nick Kyrgios, Thanasi Kokkinakis or Jordan Thompson to line up alongside Peers on Saturday.
It is a match that could potentially take Australia to a decider against France or Serbia on home soil in November in what would be a first appearance in a final since 2003.
Peers has claimed 13 ATP doubles titles since 2013 and won the Australian Open in January with Kontinen.
Hewitt knows just how important Peers is to the Australian team in the tie, which begins on Friday night (AEST) on the indoor claycourts.
"His knowledge of the doubles game is huge," he said.
"He has played against and beaten the best players and will be a key man for us."
Hewitt is thinking about playing Kokkinakis instead of Thompson in the singles matches, given the strong form he showed at the French Open in May.
Thompson, who is yet to lose in three Davis Cup matches, would then partner Peers in the doubles, with Kyrgios and Kokkinakis playing in the singles games.
Kyrgios, who will take on Steve Darcis and world No.12 David Goffin in the singles, said this was a great opportunity for he and the Australian team to make history and claim a 29th Davis Cup crown.
"It's once every blue moon you get in the semi-finals of the Davis Cup and we have a real chance to win it," Kyrgios said.
"This year is the best chance we've had in a long, long time."
Kyrgios is a huge fan of the team aspect of the Davis Cup and said Hewitt had built a great team spirit within the group.
"These are the closest friends I've got on the tennis tour," he said.
"What we are going to do now is going to last forever.
"You're not playing for yourself and I find it easier to play for these guys and I feel it's helped me so much throughout my career.
"These are the most fun weeks of my career, no doubt.
"The weeks we had in Brisbane, Melbourne, Sydney ... that is what I love about Davis Cup."
Belgium will line up with Goffin and Darcis in the singles with Ruben Bemelmans and Arthur de Greef likely to partner up in doubles.
Australia has played Belgium four times.
In recent times, Belgium has had the wood on Australia - winning on both clay and hardcourt in 2007 and 2010.