Fly-half Dan Biggar remains on the road to recovery ahead of Wales' Six Nations clash against Scotland this weekend.
Wales assistant coach Robin McBryde says Biggar is "working with the medics around the clock" in an attempt to regain full fitness.
Biggar, arguably Wales' stand-out performer during the World Cup earlier this season, limped off nursing a sprained ankle midway through the first half of last Sunday's 16-16 draw with Ireland in Dublin.
Rhys Priestland replaced him and helped haul Wales back into the contest from 13 points adrift, and he occupies pole position to start when Scotland arrive at the Principality Stadium on Saturday, should Biggar not recover in time.
Wales head coach Warren Gatland is due to name his starting line-up on Thursday.
"Dan is out of a (surgical) boot, and he is working with the medics around the clock to give himself every chance," McBryde said. "I don't think he (Biggar) is going to be training today, but he might be able to tomorrow.
"We've seen in the past that the medical team have worked wonders, really. I remember Dan Lydiate at the 2011 World Cup, where it really was a case of waking himself up every two hours throughout the night to ice his ankle, and he surprised everyone by coming back fit.
"If he (Biggar) is fit enough, he's fit enough. If he's not, he's not. It is as clear-cut as that.
"We know there is not a lot of pressure on us to make that decision because we have an able body in Rhys Priestland, which takes the pressure off having to make a decision early in the week.
"Everyone is aware of the strengths that Dan possesses with regards to the kicking game in particular, and the ability to challenge and compete as well as he does in the air.
"Rhys is a different player. He has got his own strengths, and we saw that on Sunday. He proved he is as good as anyone with regards to kicking under pressure.
"We have got ultimate confidence in Rhys. He has been in and around the squad for quite some time now. He seemed comfortable, and certainly didn't take anything away from the display on Sunday."
McBryde, meanwhile, confirmed that full-back Gareth Anscombe is fit to be considered after he was a late withdrawal from the Ireland game due to a tight hamstring, with Liam Williams taking over in the number 15 shirt.
Despite an opening weekend draw that ended Wales' Grand Slam and Triple Crown hopes, victories in their four remaining fixtures - three of which are in Cardiff - should be enough to see them crowned Six Nations champions.
It represents a tall order, but recent history certainly favours them this weekend, with Wales having reeled off eight successive wins against Scotland since Gatland took charge eight years ago.
"I think we showed on the weekend that we are not that far away. We are creating plenty of opportunities, it's just nailing them, really," McBryde added.
"It comes down to one extra pass sometimes, a little bit more depth or getting it (the ball) through your hands a bit quicker, and I am sure if we had nailed those opportunities early on, it would have been a different game, but I am sure Ireland would be saying the same thing as well.
"Having clawed ourselves back after a poor start and got ourselves three points ahead, it's then a case of switching on.
"We got that lead, and then to concede a penalty from the kick-off - I think it was a bit of an unlucky call on Tomas Francis, because he did retreat. His first movement was back, and the ball was knocked into his hands to all extents and purposes. That decision could have gone either way.
"Had we dealt with it a bit better - if we had kicked for territory and gained that territory - we would have made it very difficult for Ireland to have got out of that position on the field.
"So it was definitely one that got away, but if you'd have told us after 20 minutes that we were going to end up with a draw, we would have all taken it.
"The biggest challenge for us after a short turnaround is to make sure we have plenty of energy in the group.
"Scotland are a very canny bunch, and they come up with quite a few trick plays from first-phase, in particular. We saw that at the weekend (against England) when they came down the blindside from a lineout.
"They will be coming with a few tricks up their sleeves, and we have to be aware of that and make sure we have enough energy to react."