Wales star Jonathan Davies has admitted that he feared the worst after suffering a knee injury that stalled his World Cup campaign, and that he isn't 100 per cent for tomorrow's clash with the Springboks.

Davies will line up against semi-final opponents South Africa on Sunday following a successful fight back to fitness.

He was hurt during the pool victory over Fiji 16 days ago, and missed Wales' tense quarter-final success against France.

Scarlets centre Davies was ruled out of the entire 2015 World Cup because of a knee ligament injury sustained while playing in France for Clermont Auvergne.

"I trained fully on Wednesday and there was no reaction, so it's so far, so good," he said.

"I am confident in it, and I was just glad the scans came back all clear and I've been able to push on and get back fit.

"It was sore when he (Wales doctor) was testing it (during the Fiji game), and I did fear the worst, to be honest.

"I would like to think I know my own body quite well, and I did have a bad feeling. Thankfully, I don't know it too well! It was good news with the scan.

"On the morning of the (France) game, me and Prav (Wales' national medical manager Prav Mathema) did a few drills to see if I could get up and running, but I could tell I wasn't right.

"Prav could see it as well, and it was a case of everyone has worked too hard for me to go into the game selfishly just to play in a quarter-final.

"We made a decision that it was probably best for the team if I didn't play. Thankfully, the boys got the job done, but it was absolutely savage watching. It was terrible."

“Everyone is banged up and you have to do everything you possibly can and leaving no stone unturned in your preparation to get yourself right for some of the biggest games in your career,” he continued.

“I am probably not where I want to be, which is quite frustrating, but I know I can go out there and do a job and that’s all my goal is this week.

Davies will be a key part of Wales' bid to reach a first World Cup final as he resumes his tried and tested midfield partnership with Scarets colleague Hadleigh Parkes.

"After being injured for the last World Cup, my goal was to make the next one, and I have loved being out here," he added.

"I have been able to get back in the team and hopefully be part of something extremely special.

"There is a lot of belief in this squad - we've competed against and beaten some great teams - so we have to make sure now that there are two more 80 minutes left in us to get to what all this work is about."

At 31, Davies could struggle to make the next World Cup, while Wales head coach Warren Gatland and coaching assistants Shaun Edwards and Robin McBryde will leave their posts following the tournament in Japan.

"I heard a stat that the team that faced Australia (last month) was the oldest Wales team named at a World Cup," Davies said.

"I am not saying that we are Dad's Army, but I don't know if we are going to have another shot at a World Cup. Everything has been put into this.

"It is not just about the senior boys giving the youngsters confidence. Those young boys are able to come in and say 'yes, I'm used to beating these teams'.

"That gives us confidence in them. It has been a great dynamic, and this group has flourished over the last 18 months to two years.

"It's going to be a big one on Sunday. It's down to us 23 boys to go out there and make sure that we are still fighting for another week."