Experienced England quintet Mako and Billy Vunipola, Jamie George, Elliot Daly and George Ford have been left out of Eddie Jones' latest training squad, which contains eight uncapped players.
Among the eight uncapped players included are Gloucester centre Mark Atkinson, Harlequins flanker Jack Kenningham, wing Louis Lynagh, and hooker Sam Riley, Wasps hooker Gabriel Oghre, Sale scrum-half Raffi Quirke and prop Bevan Rodd and Northampton wing Ollie Sleightholme.
Ten British and Irish Lions from the summer tour are brought back in, as Luke Cowan-Dickie, Tom Curry, Jonny Hill, Maro Itoje, Courtney Lawes, Sam Simmonds, Kyle Sinckler, Owen Farrell, Anthony Watson and Marcus Smith are named, while previous Lions in Joe Marler, Manu Tuilagi and Ben Youngs are also included.
There are also nine players who made their debuts in England's summer series of fixtures in Jamie Blamire, Trevor Davison, Alex Dombrandt, Joe Heyes, Lewis Ludlow, Adam Radwan, Harry Randall, Marcus Smith and Freddie Steward.
"This is an exciting squad made up of experienced players and young guys who did well in the summer and have earned their place again," head coach Jones said on Tuesday.
"We have left out some experienced players but we're really clear that the door isn't closed to them, and we're looking forward to seeing them work hard to get back into contention.
"For those players the door's not closed, it's just an opportunity for them to refresh and refocus.
"They need to get back to their best. They probably haven't been at their best over the last period of time, so we are giving them the opportunity to find their best.
"They're all good players. When they are at their best, they are going to be in strong contention. But there's a lot of good young players coming through so the competition is hot.
"We are now selecting with the World Cup in mind. Almost after the Lions tour you draw bit of a line in the sand because then you're in the last two years before the World Cup and everything you do counts.
"We have five campaigns now until the 2023 World Cup so each one counts, and this is a chance for this 45 to impress the new coaching staff."
The camp will form part of England's preparations for the Autumn Nations Series in November, where they will host Tonga, Australia and South Africa at Twickenham on successive weekends between November 6 and November 20.
England's 45-man training squad
Forwards (26):
Jamie Blamire (Newcastle Falcons, 2 caps)
Callum Chick (Newcastle Falcons, 2 caps)
Luke Cowan-Dickie (Exeter Chiefs, 31 caps)
Tom Curry (Sale Sharks, 33 caps)
Trevor Davison (Newcastle Falcons, 1 cap)
Alex Dombrandt (Harlequins, 1 cap)
Charlie Ewels (Bath Rugby, 23 caps)
Ellis Genge (Leicester Tigers, 30 caps)
Joe Heyes (Leicester Tigers, 2 caps)
Jonny Hill (Exeter Chiefs, 9 caps)
Ted Hill (Worcester Warriors, 2 caps)
Maro Itoje (Saracens, 48 caps)
Jack Kenningham (Harlequins, uncapped)
Courtney Lawes (Northampton Saints, 87 caps)
Lewis Ludlam (Northampton Saints, 10 caps)
Lewis Ludlow (Gloucester Rugby, 2 caps)
Joe Marler (Harlequins, 72 caps)
George Martin (Leicester Tigers, 1 cap)
Beno Obano (Bath Rugby, 3 caps)
Gabriel Oghre (Wasps, uncapped)
Sam Riley (Harlequins, uncapped)
Bevan Rodd (Sale Sharks, uncapped)
Sam Simmonds (Exeter Chiefs, 7 caps)
Kyle Sinckler (Bristol Bears, 44 caps)
Will Stuart (Bath Rugby, 12 caps)
Sam Underhill (Bath Rugby, 24 caps)
Backs (19):
Mark Atkinson (Gloucester Rugby, uncapped)
Owen Farrell (Saracens, 93 caps)
George Furbank (Northampton Saints, 4 caps)
Ollie Lawrence (Worcester Warriors, 7 caps)
Louis Lynagh (Harlequins, uncapped)
Max Malins (Saracens, 8 caps)
Joe Marchant (Harlequins, 6 caps)
Jonny May (Gloucester Rugby, 66 caps)
Raffi Quirke (Sale Sharks, uncapped)
Adam Radwan (Newcastle Falcons, 1 cap)
Harry Randall (Bristol Bears, 2 caps)
Dan Robson (Wasps, 14 caps)
Henry Slade (Exeter Chiefs, 40 caps)
Ollie Sleightholme (Northampton Saints, uncapped)
Marcus Smith (Harlequins, 2 caps)
Freddie Steward (Leicester Tigers, 2 caps)
Manu Tuilagi (Sale Sharks, 43 caps)
Anthony Watson (Bath Rugby, 51 caps)
Ben Youngs (Leicester Tigers, 109 caps)