In a South Africa side packed with giants, it is the 5ft 7in scrum-half who stands out.

The Springboks' route to the World Cup final has been characterised by the grunt and guile of their hulking forwards and dominant physical displays.

But directing the Bok brutes around the pitch in both attack and defence has been Faf de Klerk, the blond-locked, box-kicking number nine.

So who is the scrum-half dubbed "mini Hercules" who moved to Sale Sharks to reinvent himself? And how do England stop him?

The Springbok rediscovered at Sale

It is just over three years since De Klerk made his Springboks debut in a defeat by Ireland in Cape Town, but it threatened to be a short-lived foray into international rugby.

With De Klerk in the team, South Africa lost eight of his first 11 Tests between June and November 2016.

Six months later, and with a stipulation in place meaning players with fewer than 30 caps who moved abroad could not represent the Springboks, De Klerk left South African side Lions for Sale Sharks.

England proved to be an unlikely springboard back into a green and gold jersey.

"The main thing for me when I got to Sale was I got put in a role where I needed to make a difference in the team," said the 28-year-old.

"A lot of responsibility came my way in terms of how we wanted to play, how we wanted to kick, how we wanted to play our running game.

"I started kicking for poles a lot more, started doing kick-offs. I played a lot of rugby, got a lot of starts, and the head coach Steve Diamond backed me continuously."

Eighteen months after his last cap, South Africa boss Rassie Erasmus decided De Klerk's Sale form could not be ignored and the scrum-half made a try-scoring return in the 42-39 win over England in Johannesburg in 2018.

"Coming back into the South Africa squad with Rassie and everyone we worked with in 2016, it was just a similar thing - the coach backing the players and knowing what they can bring," explained De Klerk.

"It's then up to us as players to execute whatever they give to us."

'Smallest guy on the pitch' leading the fight

A year since his return and De Klerk is now first pick among three quality South Africa scrum-halves.

He put in a man-of-the-match performance as the party-pooping Springboks squeezed the life out of Japan to knock the hosts out in the quarter-finals.

Then, asked if South Africa could win the World Cup after beating Wales in the semi-final, De Klerk simply laughed and said: "Yes."

But he has not escaped criticism at home from those who feel his kicking game often gives possession away too cheaply.

In the victory over Wales, the Springboks had just 39% of the ball and a 38% share of territory - which De Klerk says was all part of the gameplan.

"We've bought in to what we want to do every week. Part of our success is that everybody is on the same page with that," he said.

"I'm pretty excited for when I get a good kick up in the air and I can really start chasing because I know it's a 50-50."

He's not one to shirk confrontation on the pitch, either.

Footage of De Klerk going nose to nose with Wales lock Jake Ball, who stands 25cm taller than him, went viral on social media and saw the Springbok scrum-half depicted in a series of memes.

"We're great friends. It was just a nice moment between us," joked De Klerk afterwards.

"I do enjoy getting physical, it's part of the game, and you do need to be up for it, especially against a team like Wales.

"So if I can, as the smallest guy on the pitch add a bit of it, that just gives motivation to the rest. So I need to be up for it."

The 'mini Hercules' you hear before you see

Sale wing Chris Ashton, who has 44 caps for England, rates his Sharks team-mate as the "best nine in the world".

"When he's on point I struggle to find a better one," Ashton told the Rugby Union Weekly podcast.

"You cannot find a defending nine like Faf - he's smashing people. He's like a mini Hercules."

Sale flanker Ben Curry is flying to Japan to watch identical twin brother and England international Tom face team-mate De Klerk in the final.

Curry says the South African brings a great energy to the club both on and off the pitch - although the Sharks' WhatsApp group has been quieter since he's been away.

"You hear Faf before you see him," Curry told BBC Sport.

"He's very loud, he dominates and controls the room, whether that is rugby or whether it is a social situation. He is the centre of attention.

"That's great as a scrum-half, you want your scrum-half doing that. That's why he commands a game so well. He can walk into a room and command that.

"What you see on a pitch is kind of what you get off the pitch."

How do England stop him?

England scrum-half Ben Youngs described De Klerk as a "busy guy who likes confrontation" before pointing out he has already come up against two world-class opponents in the knockout stages in Australia's Will Genia and New Zealand's Aaron Smith.

However, with England having to call up Ben Spencer as a late replacement for substitute scrum-half Willi Heinz this week, World Cup winner Matt Dawson believes starting nine Youngs could become a Springbok target.

Dawson says Eddie Jones' side must pay De Klerk similar attention.

"Everything centres around Faf de Klerk," the former England scrum-half told BBC Sport.

"If you were in South Africa's shoes, would you be looking at England and thinking they have got no replacement scrum-half so they should target Ben Youngs.

"Do they try and physically intimidate him and put him off his game? That is what you would be trying to do with Faf de Klerk.

"Maro Itoje is going to try and charge down his kicks. If he has a dart around the fringes he has got to be swallowed up, swung around like a rag doll and put back down.

"If you take his energy away then South Africa are running low on other avenues to inject any kind of energy into their own team."