Wales coach Warren Gatland has named a 39-man squad for his team's opening World Cup warm-up game against England at Twickenham next week. Forwards Jonathan Thomas, Andy Powell, Scott Andrews and Ken Owens, who did not take part in Wales' training camp in Poland earlier this month, have all been brought back into the group. Scarlets back-row forward Rob McCusker misses out due to a back injury, while the other absentees from Gatland's preliminary party announced in early June include scrum-half Richie Rees, fly-half Jason Tovey, centre Andrew Bishop and hooker Richard Hibbard. Gatland still has further warm-up fixtures against England in Cardiff on August 13 and at home to Argentina seven days later before the August 22 cut-off date to announce his final 30-man squad for the World Cup in New Zealand. "The team to face England at Twickenham will be selected from this training squad," Gatland said. "We have established a nucleus of players who will form our World Cup squad based on their performances in training over recent weeks, but it is now time to translate those efforts on to the field. "The players have worked hard, but places in that final World Cup squad are still very much up for grabs and a lot will depend on what we see over the course of these next three games." Wales kick off their World Cup campaign against holders South Africa in Wellington on September 11. Wales squad for England match on August 6: Forwards - Scott Andrews (Cardiff Blues), Gethin Jenkins (Cardiff Blues), Ryan Bevington (Ospreys), Adam Jones (Ospreys), Paul James (Ospreys), Craig Mitchell (Exeter), Matthew Rees (Scarlets), Huw Bennett (Ospreys), Lloyd Burns (Newport Gwent Dragons), Ken Owens (Scarlets), Bradley Davies (Cardiff Blues), Luke Charteris (Newport Gwent Dragons), Alun-Wyn Jones (Ospreys), Ryan Jones (Ospreys), Danny Lydiate (Newport Gwent Dragons), Sam Warburton (Cardiff Blues), Martyn Williams (Cardiff Blues), Jonathan Thomas (Ospreys), Justin Tipuric (Ospreys), Josh Turnbull (Scarlets), Toby Faletau (Newport Gwent Dragons), Gareth Delve (Melbourne Rebels/AUS), Andy Powell (Sale Sharks/ENG). Backs - Lee Byrne (Clermont Auvergne/FRA), Leigh Halfpenny (Cardiff Blues), Morgan Stoddart (Scarlets), George North (Scarlets), Shane Williams (Ospreys), Aled Brew (Newport Gwent Dragons), Jamie Roberts (Cardiff Blues), James Hook (Perpignan/FRA), Jonathan Davies (Scarlets), Scott Willams (Scarlets), Gavin Henson (unattached), Stephen Jones (Scarlets), Rhys Priestland (Scarlets), Michael Phillips (Bayonne/FRA), Lloyd Williams (Cardiff Blues), Travis Knoyle (Scarlets).