Adam Jones will not play in Wales' World Cup warm-up against England on Saturday as Wales coach Warren Gatland seeks front row strength in depth.
The British and Irish Lions prop was expected to play in Cardiff as he returns from a toe injury but he and full-back Lee Byrne (knee) miss out.
Asked if Jones is fit but not selected, Gatland said: "That's right, yes.
Gavin Henson is picked at inside centre and James Hook returns from a neck injury to start at full-back.
Hooker Lloyd Burns and lock Luke Charteris will start in Wales' pack.
The Dragons pair have been picked by Warren Gatland ahead of Huw Bennett and Bradley Davies respectively as the Wales coach considers his World Cup selection with two games remaining before his final 30-man squad selection on 22 August.
Burns, who started last season as a semi-professional at Welsh club Cross Keys, will make his first Wales start alongside Paul James and Craig Mitchell in the front row on Saturday after two substitute appearances.
Wales' back row of Dan Lydiate, Sam Warburton and Toby Faletau are to start their third successive match together, a selection that gives an indication of Gatland's World Cup thoughts at the back of the Welsh pack.
But the fitness of tight-head Jones; Lions front row colleagues Gethin Jenkins, who underwent toe surgery in January, and Matthew Rees is a worry to Welsh fans a month away from their World Cup opener against defending champions South Africa.
Gatland said, however: "We weren't 100 percent happy with the way we scrummaged at Twickenham so there isn't many changes in the pack as we wanted that continuity and give those players the opportunity.
"Adam has been unfortunate for the last couple of seasons with injuries.
"He is back fit now but we've got to have contingencies that if he does get injured, having players that can come in and do a job for us."
Jones returned to training this week and he, loose-head Jenkins, hooker Rees and versatile forward Ryan Jones - all of whom have calf problems - are expected to be fit for Wales' 20 August Test against Argentina.
Leigh Halfpenny (ankle) has also returned to full training and the Cardiff Blues wing and hooker Richard Hibbard (shoulder) could feature against the Pumas.
Rhys Priestland continues at fly-half against England in Cardiff as Scarlets team-mate Stephen Jones has not recovered from a "minor" calf strain sustained just before kick-off in their 23-19 defeat to the English last Saturday.
Hook replaces Morgan Stoddart at 15 after the Scarlets player broke his left leg in Saturday's defeat at Twickenham to end his chances of playing in September's World Cup.
"We need the win this weekend - it's as simple as that," said Gatland.
"We've told the players that for us to be regarded as contenders at the Rugby World Cup we need to beat England at home this weekend, to send out that message to everyone that we are contenders."
A decision will also be taken shortly as to whether Sale scrum-half Dwayne Peel will join the squad.
Wales team to face England at Millennium Stadium on Saturday:
James Hook; George North; Jamie Roberts, Gavin Henson; Shane Williams; Rhys Priestland, Mike Phillips; Paul James, Lloyd Burns, Craig Mitchell, Luke Charteris, Alun Wyn Jones, Dan Lydiate, Sam Warburton, Toby Faletau
Replacements: Huw Bennett, Ryan Bevington, Josh Turnbull, Justin Tipuric, Tavis Knoyle, Scott Williams, Aled Brew
Wales' preliminary World Cup squad
Forwards: Scott Andrews, Gethin Jenkins (Blues), Lloyd Burns (Dragons), Huw Bennett, Ryan Bevington, Adam Jones, Paul James (Ospreys), Ken Owens, Matthew Rees (Scarlets), Craig Mitchell (Exeter), Bradley Davies, Sam Warburton, Martyn Williams (Blues), Luke Charteris, Danny Lydiate, Toby Faletau (Dragons), Ryan Jones, Alun Wyn Jones, Jonathan Thomas, Justin Tipuric (Ospreys), Josh Turnbull, (Scarlets),Gareth Delve (Melbourne Rebels), Andy Powell (Sale Sharks).
Backs: Michael Phillips (Bayonne), Lloyd Williams (Blues), Tavis Knoyle (Scarlets), Jamie Roberts (Blues), James Hook (Perpignan), Jonathan Davies, Stephen Jones, Rhys Priestland, Scott Williams (Scarlets) Gavin Henson (unattached), Leigh Halfpenny (Blues), Lee Byrne (Clermont Auvergne), Aled Brew (Dragons), Shane Williams (Ospreys), George North (Scarlets).