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

Number eight Faletau, who suffered a broken arm during Wales’ 43-19 victory over Georgia, is out of the tournament.

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

No decision has yet been made on a squad replacement for Faletau, although Aaron Wainwright is likely to switch across the back-row from blindside flanker for next Saturday’s quarter-final in Marseille.

And 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 assistant coach and 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.”

Jonathan Humphreys says that Wales “cannot afford to go off-script” when they tackle Rugby World Cup opponents Georgia in Nantes on Saturday.

Wales need a point from their Pool C finale to win the group, having already secured a quarter-final place through beating Australia by a record 40-6 scoreline nine days ago.

They lost 13-12 at home to Georgia when the countries last met almost a year ago, and Wales assistant coach Humphreys has emphasised a fierce sense of determination in the camp.

“There has been a bit of an edge about training, which is what we want,” forwards specialist Humphreys said.

“We are just keen to continue the progress that we’ve shown. That is a big driving force for us, and we have talked constantly about that.

“I expect them (Georgia) to play a bit, and they are strong up-front – we are under no illusion about that.

“They are a dangerous outfit, and we cannot afford to go off-script.”

Few could have imagined Wales reaching the last eight just 11 months after Georgia triumphed 13-12 in Cardiff, and Humphreys added: “We’ve had five months together. We are more like a club team than an international team.

“We came in earlier than most teams, we know what we wanted to improve and we haven’t deviated from that.

“Probably the messages that went out in May, they haven’t changed at all.

“Every day, it has been working on those fundamentals that we felt were important and would make a difference.”

Wales head coach Warren Gatland has made six changes for the Georgia clash, with Dewi Lake captaining a side that also sees starts for wing Rio Dyer, fly-half Gareth Anscombe, scrum-half Tomos Williams, lock Dafydd Jenkins and flanker Tommy Reffell.

Centre Nick Tompkins will continue his midfield partnership with George North, meanwhile, and look to maintain the form that has made him among Wales’ most impressive performers at the tournament.

“We want no dip in our performance,” Tompkins said.

“We want to get better, we don’t want to take our foot off the pedal – that’s the last thing we want. We want confidence and momentum and to keep on going.

“I want to just keep getting better and keep pushing myself. There are a lot of things I need to improve on.

“I am happy with some areas, but there are some things I really need to push myself on.

“You look at some of the other centres out there and how well they are doing, and you want to emulate that.

“Being together as a squad for five months means you can have those little conversations and make little tweaks.

“You are all looking for little things to tweak and improve. It has been really healthy, and it has been all of us pushing each other.”

Tompkins has also voiced his support for the World Cup bunker system, whereby incidents of foul play can be referred and a yellow card retained or upgraded to red.

“I like it,” Tompkins added.

“Decisions are tough at the moment anyway, referees are under a lot of a pressure to keep the game moving quickly and get the right decision.

“I think it is brilliant, I like that model. To cut down the pressure we put on referees, especially, is good.”