Taulupe Faletau has until Wednesday to prove his fitness ahead of Wales' trip to Italy in the opening round of the Six Nations this weekend.
The inspirational number eight was in superb form during the November internationals, but has not featured for club side Bath since their defeat to Wasps in late December due to a knee injury.
And although his recovery has been progressing well he remains a doubt for Sunday's clash in Rome as stand-in boss Rob Howley looks to make a winning start in the absence Warren Gatland.
"We're going to wait until Wednesday night to decide," said coach Shaun Edwards.
"You want your best players fit and ready, we all saw the impact he made against South Africa [a 27-13 win].
"If he's not fit, we'll have somebody else to come in and hopefully he'll be fit for England [on February 11]."
Faletau's presence could be crucial as Wales look to stop Italy's dangerman Sergio Parisse, but Edwards insists they have a plan whether their back-row forward features or not.
He added: "You have to try and double team him. Squeeze in around his offloads. We do a lot of practice of squeezing in and trailing support runners.
"It's hard to judge him sometimes because he has played in a team that has regularly lost. If he had been in an All Black team then who knows what level he could have gone to.
"He's got a new lease of life now under Conor O'Shea, he's a master motivator is Conor. Let's hope he enjoys the rest of the Six Nations, but he doesn't enjoy Sunday."