The Scarlets fly-half has been ruled out for six months after undergoing Achilles surgery, leaving the door ajar for Biggar ahead of the RBS 6 Nations.
Biggar has won 11 sporadic caps for Wales and has never been involved in a Championship encounter.
But Ospreys backs coach Gruff Rees is confident the 23-year-old can step up and fill the void at number 10.
“Dan is ready. I would back him 100 percent for that Welsh shirt,” said Rees.
“There were some frustrations for him in the autumn and he returned to us a bit rusty in one or two technical areas, but on the front foot going forward he has added so much to his attacking game.
“We know he is a good ten tactically because he has been spot on from the back end of last season through to the early months of this term.
“He needs a run of games. It’s huge opportunity for him, but he needs to play well in this weekend’s game with Toulouse, the big Christmas derbies and in our European matches next month.
“Then he can hit the ground running with Wales, which I’m sure he’ll be able to do.”
And Rees reckons Biggar would thrive if he was handed the tag of being Wales’ first-choice fly-half in the Championship, which kicks off against Ireland at the Millennium Stadium on February 2.
“He would be the type to respond like that. He has certainly done so here since we backed him,” said Rees.
“We trust him, he trusts us, and we tend to get the reward.”
Biggar and former Ospreys pivot James Hook, now at Perpignan, are the front-runners to pull on the famous jersey in the New Year but Rees was also quick to point out the talents of Wales Under-20 fly-half Matthew Morgan.
“Matthew’s made really good progress,” added Rees.
“There were technical aspects of his game that needed tightening, but he has done that, thanks to the extra work he does.
“He has responded to having a run of games and has been able to take things on board off the coaches and drive them home on the field.
“Dan is a top-end 10 who has an international track record, but Matthew is snapping at his heels.”
