Rhys Priestland looks likely to miss Wales\' World Cup semi-final against France in Auckland on Saturday, BBC Sport Wales understands.The Scarlets number 10 injured his shoulder during Wales\' 22-10 quarter-final victory over Ireland.Wales were hopeful that the injury was not serious, but the 24-year-old has not been able to train this week.It now looks as if coach Warren Gatland will have a straight choice between Stephen Jones and James Hook.Jones failed to make the 22-man squad against Ireland and Hook - who came off the bench late on - has yet to start at outside-half in the World Cup.Jones won his 102nd cap against Namibia, but since injuring his calf ahead of a World Cup warm-up game against England on 6 August he has had to play second fiddle to 24-year-old Priestland.Priestland\'s assured performance in Wales\' 23-19 defeat at Twickenham was followed by a win seven days later in Cardiff in which he also impressed.Hook took over at fly-half when Wales ended their pre-tournament campaign with victory over Argentina.Priestland, who was set to win his 10th cap in Saturday\'s semi-final against France, started three of Wales\' Pool D games - the 17-16 defeat by South Africa, the 17-10 victory over Samoa and the 66-0 rout of Fiji.And despite Hook having recovered from a shoulder injury he suffered playing full-back against Samoa and Jones\' calf problem clearing up, Priestland has held on to the pivot role.Wales coach Warren Gatland has been particularly impressed by Priestland\'s coolness under pressure.As well as Priestand, Luke Charteris, Jamie Roberts, George North and skipper Sam Warburton all sat out training on Tuesday.But apart from Priestland Wales are likely to pick from a full squad.