Paris - Yannick Noah's France take on star-starved Serbia and 28-time champions Australia face Belgium in the Davis Cup semi-finals this weekend.
Lucas Pouille leads hosts France into battle in Lille against Dusan Lajovic in Friday's opening singles.
That's followed by French number one Jo-Wilfried Tsonga crossing swords with Davis Cup debutant Laslo Djere, the highest-rated Serbian at No.80 in the world.
Noah's team are favoured to progress to the final against a Serbian side sorely missing injured former world No.1 and 12-time Grand Slam winner Novak Djokovic, Viktor Troicki and Janko Tipsarevic.
But Pouille insisted despite their rankings superiority the semi-final was no foregone conclusion for France.
"We are not over confident, we've got an enormous amount of respect for this team (Serbia) which has a lot of very good players," said Pouille, who was beaten in the fourth round at the US Open.
A similar note of caution was sounded by Noah ahead of the tie being held on the same clay where France lost the 2014 final to Roger Federer's Switzerland.
"We are sufficiently intelligent to know that it's going to be a difficult match," the 1983 French Open winner said.
"Even if their players aren't at the top of the rankings they've got nothing to lose. We won't be playing an exhibition match this weekend."
Serbia won their sole Davis Cup title in 2010, beating France in Belgrade 3-2.
France, who secured their ticket to the semi-finals after seeing off Great Britain 4-1 in the last eight, are seeking a 10th title but first in 16 years.
In Brussels, Belgium's David Goffin (ranked 12 in the world) will be out to embellish his phenomenal record in the competition against 185th ranked Australian John Millman.
Millman's appearance in the opening singles represented a surprise with the slot expected to go to Thanasi Kokkinakis.
Aussie coach Lleyton Hewitt explained the switch, telling the Davis Cup's official website: "John is match hardened, he's played a lot of five-set tennis, particularly in New York. We have full belief in that he can do the job for us."
Goffin, ranked No.12 in the world, has won 13 of his 14 Davis Cup matches, the lone loss coming in the 2015 final to Britain's Andy Murray.
Belgian's medical team have been working round the clock to ensure Goffin's presence after the Belgian star injured his left knee at the US Open.
"I feel good, everything's OK," Goffin told Belgian radio RTBF.
"My knee hurt after the US Open, but day by day it got better so I told (coach) Johan Van Herck that I was 100 percent available for the team."
Goffin, the ninth seed in New York, was stunned by Russian teenager Andrey Rublev 7-5, 7-6 (7/5) in the fourth round.
Next up on the indoor clay court in the Belgian capital Australia's gifted but combustible Nick Kyrgios (20th) faces 33-year-old Steve Darcis (77).
Kyrgios, who helped Australia beat the United States in the quarters, was picked by Hewitt despite his first round exit at Flushing Meadows.
The victorious semi-finalists will meet in the 2017 final scheduled for the end of November.