Wales could know more in the next 24 hours or so about fly-half Dan Biggar's prospects of facing RBS 6 Nations opponents Scotland next Saturday.
Biggar went off just 22 minutes into Wales' 16-16 draw with reigning Six Nations champions Ireland in Dublin.
He was replaced by Rhys Priestland, whose goalkicking helped haul Wales back into the contest from 13-0 adrift, with head coach Warren Gatland confirming afterwards that Biggar had suffered a sprained ankle.
"Dan has a high ankle sprain, so we will know more on that in the next 24 to 48 hours," Gatland said.
"Whether he has got to be scanned or not, I don't know. It's difficult to make assessments so soon after the game.
"I thought Rhys Priestland played well when he came on, and we were happy with his performance."
Full-back Gareth Anscombe, meanwhile, who had been selected to start the game, withdrew because of a tight hamstring and was replaced by Liam Williams.
Gatland added: "Gareth's hamstring was tight on Friday, so we pulled him out of training and Liam ran there all day on Friday.
"We made the decision that it wasn't worth the risk of starting Gareth, particularly as we didn't have a huge amount of full-back cover."
Three of Wales' remaining four Six Nations games this season are at home, and skipper Sam Warburton accepts that victories in Cardiff against Scotland, France and Italy are essential, while they also face a Twickenham appointment with England next month.
"We have got three home games out of four now, and they are must-win matches," Warburton said.
And Wales centre Jamie Roberts added: "It is a draw. We won a championship in 2013 after losing a game, and we all know what happened last year when teams dropped a game.
"So the championship is wide open. If we win our next three games, we will be in with a shout.
"Scotland are an impressive team. They were desperately unlucky in the World Cup, and I was rooting for them against Australia.
"Vern Cotter has really taken them on. They have quality players within their side, and they will cause us a huge threat.
"A draw is a draw, and we look forward to Scotland on Saturday."