The Scarlets fly-half ruptured his Achilles against Exeter Chiefs last Saturday and face six months on the sidelines after undergoing surgery.
“I’m hugely disappointed to lose such a talented player,” said Howley.
“He turned his performances around in the autumn and had one of his best games in a Wales jersey against Australia, that spoke volumes about him.
“But the key thing now is to get the injury right. He’s shown great character over the last four weeks and I’m sure that fortitude will come in over the next six months.”
Despite the loss of Priestland, Howley is confident Wales have the strength and depth to cope in the Championship.
“We have good competition at 10 with Dan Biggar and James Hook,” added Howley.
“They are hugely skilful players and Dan was one of the form players going into the autumn.”
Priestland could still return to action before the end of the 2012-13 season and his national and regional teammate Jon Davies, whom he shares a flat with in Cardiff, reckons he will come back stronger.
“It’s huge blow and a bad injury. It’s been a tough couple of months for him but I’m sure Rhys has got the character to bounce back from this.
“He had a tough couple of weeks at the start of the autumn then started to come through it. He could probably see light at the end of the tunnel then to have this is a major blow.
“It’s a big loss for the Scarlets and Wales. Rhys is a world-class player, he’s our 10 and plans the tactics on the field.”
Davies has also experienced long-term periods on the sidelines but he reckons the hardships strengthen players’ resolve and he has promised to keep a close eye on his flatmate.
“You’ve got to keep yourself occupied,” added Davies.
“For most of the first couple of weeks you will be on the sofa. You have to keep yourself mentally fresh otherwise you will go mental.
“It is a tough time but these injuries make you a stronger player – you want to be on the field more. Hopefully, it will work as a positive in the long-term.
“He was okay at the weekend. He has come to terms with it but it’s a bitter pill to swallow. Saturday night the flat was a pretty dim place.
“We had to look after him and give him a bit of a cwtch. Fenby (Andy) has got a bell for Rhys to ring!”
