Hook and Biggar vie for Wales No 10 shirt after Priestland ruled out of Six Nations
Wales star Rhys Priestland has been backed to cope with the mental and physical agony of an injury that means he will miss the Six Nations.
The Scarlets out-half's hopes of touring Australia with the Lions next summer also appear to be over after he suffered a ruptured Achilles tendon.
The 25-year-old, who sustained the damage in last weekend's Heineken Cup game against Exeter, underwent surgery yesterday and faces six months out of action, adding to Wales' injury woes.
Prop Aaron Jarvis, lock Alun-Wyn Jones and flanker Dan Lydiate are almost certainly out of the opening clash with Ireland, while full-back Leigh Halfpenny, centre Jamie Roberts and lock Ian Evans are major doubts.
With Priestland sidelined, interim head coach Rob Howley would appear to have a straight choice between Perpignan's James Hook and Ospreys' Dan Biggar at No 10.
"It's a big blow for Rhys and for our region to lose a player of his quality and influence," said Scarlets head coach Simon Easterby, a former Ireland back-row.
"He was coming through well in the last couple of games of the autumn, put in a strong performance against Australia and was making a real impact on our game against Exeter, so it's very difficult for him to take.
"But he will get plenty of support from here throughout the injury period.
"I am sure that a player of his experience, intelligence and ability will deal with this very well, and after a couple of weeks away to recover from the surgery he will be back and can be a very positive influence in our environment.
"We all want to show him as much support as we can. It's going to be tough to take, but the boys here are a very close-knit group so that will be a positive for him."
Priestland, who has won 22 Test caps, was a driving force behind Wales' outstanding push to reach the World Cup semi-finals in New Zealand last year.
He then featured prominently during last season's Grand Slam campaign and although his form dropped off, he remained a key member of the team, starting three of their four autumn Tests and going on as a substitute against Samoa.