Scarlets are not expecting Sam Costelow to return until January after the Wales fly-half picked up shoulder and hamstring injuries during the 49-26 win against Barbarians last Saturday.
Costelow was replaced at half-time by Dragons’ Cai Evans after suffering injury scoring Wales’ third try in the uncapped match in Cardiff.
He is the favourite to be Wales’ fly-half during the 2024 Six Nations.
Wales open the tournament against Scotland in Cardiff on 3 February.
Costelow is expected to miss at least six United Rugby Championship (URC) matches and the opening two rounds of Europe’s Challenge Cup.
“He has a hamstring tear and a shoulder issue so we are not expecting him back in the short-term,” said Scarlets head coach Dwayne Peel.
“It will be beyond Christmas and the new year before we see him. I do not have an exact date and we are still waiting on the final prognosis and some specialist opinion on that.
“It is disappointing for us because he is going to be out for the larger part of the first half of the season.
“There is loads more to come from him and this is an injury setback in his career.
“He is becoming an all-rounded player and that has just come from time which is what you need as a 10.
“I am sure he will fulfil what promise we think he has. He has been excellent for us over the last year and his leadership has grown and the next step is to go to that next level.”
Centre Johnny Williams also picked up a hamstring injury during the Wales match and will have a scan to determine the extent of that problem. Williams will definitely miss Saturday’s league home game against Lions.
The Barbarians game was the same day Scarlets defeated Cardiff in a URC derby, a fixture clash that Peel last week had described as unhelpful and frustrating.
“It is disappointing for us because they are two international quality players and have done very well for us,” said Peel.
“It is a bitter pill, but we have to move on and make sure we prepare well and it’s an opportunity for others.
“Ioan Lloyd will get an extended run in that 10 slot and it’s good for him because I thought that was his best game for us in terms of controlling the game.
“We know what an exciting talent he is in terms of ball in hand, but in terms of controlling the game he was very good.”
Wales fly-half poser
Costelow is expected to step into the Wales number 10 berth vacated by the retirement of Dan Biggar and departure of Gareth Anscombe to Japan.
The 22-year-old made his first Test start in the summer friendlies against England, featuring again against South Africa before appearing in four of Wales’ five games at the World Cup.
Rhys Patchell, Joe Hawkins and Jarrod Evans have made themselves ineligible for international selection after moving to clubs outside Wales – in New Zealand and England – while Rhys Priestland left Cardiff at the end of 2022-23 and has indicated he is unlikely to play again.
Callum Sheedy is available, with Wales head coach Gatland stating he will be going to watch the Bristol playmaker in action, while the New Zealander has also name-checked Dragons young fly-half Will Reed.
Gatland also stated he would like to see Cardiff centre Ben Thomas play at fly-half and even indicated scrum-half Tomos Williams could fill in at number 10.
Against Barbarians, Evans initially came on at fly-half before Gatland brought on Kieran Hardy at scrum-half while switching Cardiff’s Williams to the stand-off role.
Costelow’s Scarlets team-mate Lloyd may also be an option, while Ospreys’ Owen Williams started games in the 2023 Six Nations and was part of the extended World Cup training group before being left out of the final 33-strong squad.