Ospreys fly-half Luke Price will be out until at least January after breaking his leg in Friday's opening Pro14 win over Edinburgh.
The 22-year-old got the nod over Sam Davies to start against Edinburgh, as Ospreys look for a long-term successor to British and Irish Lions tourist Dan Biggar, who has joined Northampton.
But Price was hurt late in the first half of the game in Swansea.
The injury does not require surgery, but Price needs lengthy rehabilitation.
"It is hugely disappointing," said Ospreys head coach Allen Clarke.
"Luke is a fine young man, he has youth on his side and he has shown resilience before and he will come back and it will be this season, which is great."
Davies and James Hook will cover the number 10 position alongside Wales Under-20s outside-half Cai Evans.
It was a surprise when Davies was left on the bench against Edinburgh and the Wales international excelled in the victory after coming on as a replacement.
"Sam and James are quality players," said Clarke.
"You could see on how Sam marshalled us around the field against Edinburgh.
"We were delighted with the cohesion he showed and James has trained fantastically well during the summer."
When asked whether the Ospreys bring in fly-half cover, Clarke added: "Possibly, depending on what is out there.
"It has to be the right person and the right quality.
"We will concentrate on the boys we have at the moment. It is just something we need to monitor."