It goes without saying that few coaches would choose to blood a player in the furnace of a World Cup semifinal - but Lievremont is among those few coaches.
"He hasn't donned the Blues strip yet," Lievremont said.
"If he's here it isn't by coincidence. I have great faith in him."
Lievremont also confirmed that Parra will take over goalkicking duties from Yachvili.
Wales have made no late changes as they seek to go where no other team from the Principality has gone before. They did have a selection dilemma of their own during the week as classy first five-eighths Rhys Priestland failed to recover from a shoulder injury suffered late in their quarter-final against Ireland.
Bad news for Wales, yes, but even worse news for France apparently.
"It's not great news for us," Lievremont said. "Priestland is an excellent player but Hook is nonetheless an experienced player and Wales will undoubtedly be much stronger with him."
It's a curious semifinal in so many ways. Before the tournament started few would have pegged this as a likely final-four fixture. That number would have reduced further as France stumbled their way embarrassingly through Pool A with a two-win, two-loss record.
But there we are and there are enough cameras to turn a young man's head.
"It's mad, I've never seen so much media attention in my life," said 22-year-old fullback Leigh Halfpenny. "For every single one of us it's new territory."
Halfpenny is expecting an aerial bombardment from the combined kicking threats of Yachvili and Parra and plans to own the air.
"I've always loved that part of the game," he said.
The World Cup final has remained elusive to Wales since the day they were beaten 49-6 in Brisbane 24 years ago. France have played five semifinals, three of them epics. In 1987 they scored a dramatic late try in the corner to beat Australia. In 1995 they lost a game they felt they had won on a waterlogged pitch in Durban. Four years later they destroyed the All Blacks with 20 of the craziest minutes ever played.
In the past two World Cups they've limped out to England in the final four, so will no doubt be pleased to see a different-coloured shirt.
"In 2007 we relaxed too much and we thought we had won the game before we played it against a team that was not as experienced as we were," said No 8 Imanol Harinordoquy, whose return to form against England last weekend coincided with France's best performance at the tournament.
"We have to be of better mind. It is a dream. All my life I have wanted to play in a final of the World Cup."
France v Wales: Key match-ups
Dimitri Yachvili v Mike Phillips
The shrewd tactician versus the bustling extra forward?
It's a sharp contrast in styles at halfback, but both were extremely influential in their sides' respective quarter-final wins against England and Ireland. Yachvili offers organisation and kicking skills from the base, whereas Phillips is a real danger with his running game, as he showed when he darted a narrow blind and had the strength to shrug off a defender before planting the ball in the corner.
Yachvili, who comes into the match under an injury cloud, combines well with fellow halfback Morgan Parra, who is listed at No 10. Both can fulfil the playmaking role. If there is a criticism, Yachvili can go missing when France is on the back foot.
Phillips, who played flanker into his late teens and is one of the game's biggest halfbacks, will not shirk the tough stuff. His ability to break the advantage line and get his forwards on the front foot is highly valued. Wales are a team who have placed a lot of stock in their tackling. Again, Phillips is more akin to a loose forward than an inside back in this regard.
His clearance will never be as sharp as other great halfbacks, but his upside in other areas is huge.
Thierry Dusautoir v Sam Warburton
In fact, enlarge this to a fabulous contest in prospect between Wales' and France's loose forward trios tonight.
This pair have three things in common: they lead their respective countries, they are loose forwards and they're players of the highest order.
Dusautoir's star rose swiftly on the back of his remarkable performance when France beat the All Blacks four years ago in the quarter-final in Cardiff, where he registered a barely credible 38 tackles.
At 29, and preparing for his 47th test, he is a quiet achiever with rock-like defensive qualities and a strong support player.
In partnership with No 8 Imanol Harinordoquy and Julien Bonnaire, he formed an outstanding loose forward trio which comprehensively outplayed their English rivals in last weekend's quarter-finals.
If Dusautoir has been hailed as Europe's most influential flanker, Warburton looks set to take the mantle.
Just 23 years old and playing his 18th test tonight, Warburton has been terrific throughout the World Cup.
Before Wales' opening game against South Africa, coach Warren Gatland talked of Richie McCaw, Heinrich Brussow and David Pocock as the big three fetchers in the game. Warburton, he opined, would be joining them shortly.
Throughout the cup he has been uncommonly good, hugely influential and, as Dusautoir remarked yesterday, he looks to be "in for the long haul".
