England manager Martin Johnson admitted injuries were a concern as he left New Zealand-born centre Riki Flutey out of his 30-man World Cup squad here on Monday. Johnson named four players -- prop Andrew Sheridan, wing Chris Ashton, scrum-half Ben Youngs and captain and World Cup winning flanker Lewis Moody -- in his 30-man squad for New Zealand despite the quartet being hampered by injury. Of the four only Moody has had a run-out in England's two warm-up games against Wales so far and he only lasted for 61 minutes of the first Test at Twickenham before retiring with knee injury. Johnson also had to cope with the loss of scrum-half Danny Care, who needed surgery on his toe, ruling him out of the tournament, following the second Wales game in Cardiff and that has impacted on his selection elsewhere. Care's absence persuaded Johnson to include Wasps' uncapped Joe Simpson as one of a trio of scrum-halves where previously the former England captain may have used full-back Ben Foden and Flutey as cover. Flutey missed out on a trip to his native New Zealand and Johnson revealed cutting him from a squad where England are still travelling with players yet to prove their fitness was one of his toughest decisions. "In an ideal world they would all be in great form with game time but we don't live in that world," Johnson told reporters at England's training camp, south-west of London, on Monday. "Lewis is an important piece of what we do. So is Ben and so is Andrew Sheridan. We anticipate them being ready to go in the World Cup," added Johnson, captain of the only England side ever to have won rugby union's showpiece event, back in 2003. "Ben Foden can do a bit at nine and Riki can do a bit. "But in the harsh light of day, if one of your nines gets injured going into a big game you are one injury away from someone who doesn't play nine having to start in that position. "Do we take two scrum-halves with the flexibility we have? We just felt we couldn't do that, it was too big a risk because if you lose one three days before the game, being so far away, it leaves you under pressure. "Any solution leaves you slightly thin somewhere. It was tough on Riki, who has done nothing wrong and it was a really tough call," the former lock added. "We just felt that was the best way to go squad-wise. "Riki adds a lot to the group off the field, a lot of energy. He is a top guy. He took it very well, which doesn't make it any easier for me." Flutey played for the British and Irish Lions in 2009 but injuries and an unsuccessful spell with French club Brive checked his progress, allowing fellow New Zealand born-back Shontayne Hape, a former Kiwi rugby league international, to establish himsel as England's inside centre. Johnson is also mindful of the physicality of the Argentinian and Georgian packs, both in England's pool, hence his decision to pick five props -- Alex Corbisiero, Sheridan, Dan Cole, David Wilson and Matt Stevens. "You go through all the options and possibilities. We have gone for five props because of the attrition rate," said Johnson. England are aiming to appear in a third successive World Cup final, having lost in the climax to South Africa four years ago in Paris. Aside from Moody, others remaining from the 2003 triumph are Jonny Wilkinson - who dropped the matchwinning goal against hosts Australia - hooker Steve Thompson, lock Simon Shaw, who joined the squad midway through the tournament as a replacement, and centre Mike Tindall. Squad: Forwards (17): Dan Cole (Leicester), Alex Corbisiero (London Irish), Tom Croft (Leicester), Louis Deacon (Leicester), Nick Easter (Harlequins), Dylan Hartley (Northampton), James Haskell (Ricoh Black Rams/JPN), Courtney Lawes (Northampton), Lee Mears (Bath), Lewis Moody (Bath, capt), Tom Palmer (Stade Francais/FRA), Simon Shaw (unattached), Andrew Sheridan (Sale), Matt Stevens (Saracens), Steve Thompson (Wasps), David Wilson (Bath), Tom Wood (Northampton) Backs (13): Delon Armitage (London Irish), Chris Ashton (Northampton), Matt Banahan (Bath), Mark Cueto (Sale), Toby Flood (Leicester), Ben Foden (Northampton), Shontayne Hape (London Irish), Joe Simpson (Wasps), Mike Tindall (Gloucester), Manu Tuilagi (Leicester), Richard Wigglesworth (Saracens), Jonny Wilkinson (Toulon/FRA), Ben Youngs (Leicester).