England expect Bath centre Ollie Lawrence and Harlequins hooker Jack Walker to be available for World Cup selection after they both suffered injuries during training.
Premiership player of the season Lawrence is recovering from a knee injury, while Walker has a calf muscle problem.
Both players were hurt in England squad training last week and they are understood to each be facing a minimum of six weeks’ rehabilitation.
England’s opening World Cup warm-up game is against Wales in Cardiff on August 5, while head coach Steve Borthwick is due to name his final 33-player squad for the tournament two days later.
Lawrence and Walker will join a 38-strong group for treatment during England’s preparation camp in Brighton this week.
Borthwick’s training resources have been bolstered by players from beaten Premiership semi-finalists Leicester and Northampton.
The likes of Courtney Lawes, Ben Youngs, Dan Cole, Freddie Steward, Anthony Watson, Lewis Ludlam, Alex Mitchell and Tommy Freeman all feature.
Saracens number eight Billy Vunipola, Leicester forward Ollie Chessum and Exeter hooker Luke Cowan-Dickie all remain in camp to continue their rehabilitation from injury.
Players from Premiership finalists Saracens and Sale, meanwhile, remain on rest periods.
There are no places for London Irish wing Ollie Hassell-Collins, Bristol scrum-half Harry Randall and Bath number nine Ben Spencer, who were all part of last week’s 28-strong training contingent.
Borthwick said: “We are pleased to welcome players from Northampton Saints and Leicester Tigers, who can now start to integrate themselves into the group, and we look forward to players from Sale Sharks and Saracens joining us in a fortnight.
“The first phase of our preparation continues to focus on ensuring the players are physically equipped for what we need to do in a World Cup campaign.
“That means the training will be tough and purposeful. The players are rising to the challenge.
“We will work hard again this week and we will enjoy some time together off the field too, which is also an important part of our preparation.”
Training squad:
Backs – H Arundell (London Irish), D Care (Harlequins), J Cokanasiga (Bath), F Dingwall (Northampton), T Freeman (Northampton), W Joseph (London Irish), J Marchant (Harlequins), J May (Gloucester), A Mitchell (Northampton), C Murley (Harlequins), G Porter (Leicester), H Slade (Exeter), F Smith (Northampton), M Smith (Harlequins), F Steward (Leicester), J Van Poortvliet (Leicester), A Watson (Leicester), B Youngs (Leicester).
Forwards – J Blamire (Newcastle), D Cole (Leicester), A Dombrandt (Harlequins), T Dunn (Bath), C Ewels (Bath), E Genge (Bristol), J Heyes (Leicester), T Hill (Bath), C Lawes (Northampton), L Ludlam (Northampton), J Marler (Harlequins), G Martin (Leicester), Z Mercer (Montpellier), B Obano (Bath), T Pearson (London Irish), V Rapava-Ruskin (Gloucester), D Ribbans (Northampton), K Sinckler (Bristol), W Stuart (Bath), S Underhill (Bath).
