Billy Vunipola has suffered another World Cup setback after the England No8 underwent minor knee surgery last week.
The Saracens powerhouse is battling to beat a knee problem in time to feature in England's World Cup warm-up matches in August.
England still expect him to be fit in time for the four preparatory Tests, before the World Cup kicks off in France in September.
Vunipola said: "The medical team are positive about my prospects and I understand what needs to be done over the next few weeks."
England say Vunipola "underwent a minor surgical procedure" on Friday, and the 30-year-old will continue his rehab at the World Cup training camp.
Steve Borthwick has trimmed his squad from 38 to 36 for the week ahead, with Beno Obano and Will Joseph dropping out.
Training squad in full
Forwards: Jamie Blamire (Newcastle Falcons), Dan Cole (Leicester Tigers), Alex Dombrandt (Harlequins), Tom Dunn (Bath Rugby), Charlie Ewels (Bath Rugby), Ellis Genge (Bristol Bears), Joe Heyes (Leicester Tigers), Ted Hill (Bath Rugby), Courtney Lawes (Northampton Saints), Lewis Ludlam (Northampton Saints), Joe Marler (Harlequins), George Martin (Leicester Tigers), Zach Mercer (Montpellier Herault Rugby), Tom Pearson (London Irish) ,Val Rapava-Ruskin (Gloucester Rugby), David Ribbans (Northampton Saints), Kyle Sinckler (Bristol Bears), Will Stuart (Bath Rugby), Sam Underhill (Bath Rugby)
Backs: Henry Arundell (London Irish), Danny Care (Harlequins), Joe Cokanasiga (Bath Rugby), Fraser Dingwall (Northampton Saints). Tommy Freeman (Northampton Saints), Joe Marchant (Harlequins), Jonny May (Gloucester Rugby), Alex Mitchell (Northampton Saints), Cadan Murley (Harlequins), Guy Porter (Leicester Tigers), Henry Slade (Exeter Chiefs), Fin Smith (Northampton Saints), Marcus Smith (Harlequins), Freddie Steward (Leicester Tigers), Jack van Poortvliet (Leicester Tigers), Anthony Watson (Leicester Tigers), Ben Youngs (Leicester Tigers)