Jonathan Davies has urged Wales not to "throw" Cardiff Blues teenage fly-half Rhys Patchell into the Six Nations.
The 19-year-old has earned plaudits for his Pro12 and Heineken Cup displays.
But ex-dual code star Davies says interim Wales boss Robert Howley should choose between Osprey Dan Biggar and Perpignan's James Hook.
"It wouldn't be a good idea to throw him [Patchell] in while Wales are under this pressure in the Six Nations," Davies told Scrum V.
"I have no doubt he will play for Wales and he'll have a long and distinguished career at regional and international level.
"But at the moment leave him to learn his trade at this level.
"He has got a bit about him. He does communicate, he shouts and screams at people - you need a bit of edge at stand-off.
"But let's calm down a little bit now. He is 19, Biggar and Hook are above him in the pecking order.
Patchell was man-of-the-match as the Blues beat Munster 17-6 in the Pro12 at the weekend, the latest in a series of impressive displays for his region.
In December Davies called for in the wake of the torn Achilles that has ruled Scarlet Rhys Priestland out of Wales' Six Nations defence.
Hook has also been injured recently, damaging a shoulder, but is expected to return to French Top 14 action ahead of Wales' 2 February Six Nations kick-off against Ireland in Cardiff.
But Davies says Wales must make a straight choice between the Perpignan pivot and Biggar, who overtook Hook in the Ospreys pecking order while they were team-mates.
Davies also says Wales should have relieved Priestland of the fly-half burden during a run of 2012 form that
"You've got Dan Biggar who is, week in, week out, the best number 10 in Wales without a shadow of a doubt," said Davies.
"Even when Rhys Priestland was fit he [Biggar] was the best number 10.
"Then you've got James Hook who is now playing regularly at 10 for Perpignan.
"I don't know what their [the Wales' selectors] thoughts are.
"One, do they think that Dan Biggar is good enough to play that role for Wales?
"And secondly, do they then think Hook can run a game for Wales at number 10?
"Those are the two options that they have. Okay?
"And now they've got to go with one of them.
"That's the call they have to make and whatever they do they've got to stick with it."