Wales have confirmed that 19-year-old uncapped Newport Gwent Dragons centre Tyler Morgan will be part of their World Cup training squad.
Head coach Warren Gatland has moved quickly after Jonathan Davies was ruled out of World Cup contention due to a serious knee injury.
Although Gatland has not yet named his extended squad for tournament preparations this summer, he has revealed that Morgan will be included.
Morgan has been withdrawn from Wales' squad for the forthcoming World Rugby Under-20 Championship in Italy. He signed a national dual contract earlier this season, and he was part of Wales' 2015 Six Nations squad.
"We are delighted to have a player of Tyler's calibre and potential to call on," Gatland said.
"It is unfortunate that he will miss out on the World Rugby U20 Championship, but the decision we have taken now will give him the chance to focus entirely on this opportunity."
Davies was hurt playing for Clermont Auvergne against French Top 14 opponents Montpellier last Saturday, and he now faces surgery to repair a ruptured anterior cruciate ligament.
Davies, who has won 48 caps and played in all three Tests for the Gatland-coached 2013 British and Irish Lions against Australia, is expected to face a lay-off of six to seven months.
He would have been an integral part of Gatland's World Cup squad, with his midfield partnership alongside Jamie Roberts proving to be a bedrock of recent Wales' successes.
Gatland added: "It's a disappointment for Jonathan and for us, but the advice is for him to have the surgery straight away.
"Obviously, the injury rules him out of the 2015 Rugby World Cup, but our focus is his long-term career.
"And we will be working closely with him during his recovery, looking towards the 2016 RBS 6 Nations."
Experienced Scarlets centre Scott Williams would be the obvious replacement for Davies in Gatland's starting line-up.
Wales' opening World Cup fixture is against Uruguay in Cardiff on September 20, with key England and Australia matches both taking place at Twickenham. They will prepare for the tournament with warm-up encounters against Ireland (home and away), plus Italy.
Source: PA
