Scarlets scrum-half Kieran Hardy has been called into Wales’ World Cup squad.

Number eight Taulupe Faletau was ruled out of the remainder of the tournament after suffering a broken arm during Wales’ 43-19 victory over Georgia on Saturday.

But Wales feel they have enough existing back-row options to cover Faletau’s absence and Hardy, who will join the squad in Versailles on Sunday night, will increase scrum-half resources alongside Gareth Davies and Tomos Williams.

Wales head coach Warren Gatland said: “We feel we have a number of options in the back row at the moment, so we’ve decided to call up Kieran to give us extra cover at scrum-half and to take some pressure off from a training perspective.”

Hardy was left out of Wales’ initial World Cup squad after Gatland opted to select only two scrum-halves in Davies and Williams.

Wales assistant coach Jonathan Humphreys admits Wales’ mood after topping their World Cup group with an unbeaten record has been tempered by injuries to Faletau and Gareth Anscombe.

Fly-half Anscombe withdrew 45 minutes before kick-off against Georgia in Nantes due to a groin injury.

In terms of replacing Faletau against quarter-final opponents Argentina next Saturday, Aaron Wainwright is likely to switch across the back-row from blindside flanker.

Full-back Liam Williams was on crutches after the Georgia game following a blow to his knee but, while he could miss training in the early part of this week, Wales are hopeful about his quarter-final prospects.

“It is a big loss, he is a true world-class player,” Wales forwards specialist Humphreys said of Faletau.

“He is great around the place, but in a tournament these things happen and we have been very lucky in terms of the amount of injuries that we’ve had.

“But it still doesn’t detract from the loss of him. We will have a look over the next 24-48 hours (about a replacement) and make a decision then.

“You can’t replace what Toby (Faletau) gives, in terms of his intelligence and what he does, how he always turns up at the right place and makes the right decision at the right time.

“There is a huge onus now on everybody else to bring more.

“We are delighted that we topped the group, but then when you have close members of the squad who have been injured you are clearly down about that. It affects the mood.

“It is a tough one for Toby, but hopefully Gareth won’t be too long. He felt something in the warm-up and (we) made the decision not to play him. We will know over the next 36 hours what his chances are.”

If Wainwright moves positions, the vacancy at blindside flanker could mean a recall for seasoned campaigner Dan Lydiate, while Exeter’s Christ Tshiunza is also an option, along with switching captain Jac Morgan from openside and handing Tommy Reffell the number seven shirt.

Humphreys added: “We are blessed with the options that we have, but it still doesn’t detract from fact that Toby has been a massive player for us. Whoever steps in I am sure will step up to the plate.

“I think Aaron has been exceptional and I and he know there is more in him.”

Anscombe’s injury meant a late call to the starting line-up for Sam Costelow, while Dan Biggar is continuing his recovery from a pectoral muscle strain and should feature in Marseille.

“There is no thinking, you just have to do what you’ve got to do for the best of the team,” Costelow said, following his sudden elevation from the bench.

“Those senior boys talking to me, just telling me to do my job and to relax, that was massive for me, especially as a young 10. I am just glad we got the job done.

“You can never switch off, especially in this pressured environment. You have got to be ready at all stages. I did my homework, I knew the role and luckily it went well.”