We have been impressed with what we have seen in the Premiership and European Cup
England coach Stuart Lancaster recalled a couple of big guns for his team's year-end Tests against the three Southern Hemisphere powerhouses.
Lancaster named a 32-man squad on Thursday for the internationals against Fiji, Australia, South Africa and New Zealand.
The England coach was forced into changes by injuries to Ben Foden, Tom Croft, Alex Corbisiero and Rob Webber, and the retirement of Charlie Hodgson, Matt Stevens and Lee Mears.
Lancaster promoted James Haskell, Ugo Monye, Mako Vunipola and Tom Youngs from the England Saxons squad as injury replacements for Croft, Foden, Corbisiero and Webber respectively.
He also recalled Courtney Lawes and Tom Wood, after they missed England's mid-year tour to South Africa through injury.
Saracens prop Vunipola, 21, replaces Corbisiero - who required surgery on a knee injury sustained in South Africa - having represented England at Under-18 and Under-20 levels.
Northampton fullback Foden is out with a damaged ankle, while Leicester's Croft is out with a neck injury.
Bath's Webber is recovering from a shoulder problem.
"As a coaching team we can't wait to go into camp and get the guys focused on what will be a massive challenge in the year-end Tests - Fiji and then the three major Southern Hemisphere teams in successive weeks," Lancaster said.
"We have been impressed with some of the rugby we have seen in the Premiership and European Cup and are looking forward to the players bringing that form to Twickenham.
"It's great to be able to give Mako a chance in the squad. He has come through our age grade sides and made a real impact at Saracens. Likewise Tom Youngs, who was with us on tour in South Africa, and we know what James Haskell and Ugo Monye are capable of if they get their opportunity.”
England will be at the Football Association's new sports training and development centre from Sunday, October 28, to Thursday, November 1, before returning to their usual training base of Pennyhill Park, Bagshot on Sunday, November 4 ahead of the Test against Fiji.
* Meanwhile, the England Saxons coaching team has been finalised, with John Fletcher joining as backs coach for the internationals against the Ireland Wolfhounds and Scotland A in the New Year.
The former Newcastle Falcons boss returns to Kingston Park on Friday, February 1 for the match against the Scots, a week after the Saxons face the Wolfhounds in Ireland.
Fletcher, the England Under 18 Head Coach and RFU's Professional Player Development Manager, will join Head Coach Jon Callard, with Simon Hardy responsible for the forwards.
Callard said: "We are delighted to have John on board as we focus on winning two demanding games. His expertise working with a wide group of players makes him a perfect fit for England Saxons and he'll bring tremendous passion to the role."
Forwards: Mouritz Botha, Dan Cole, James Haskell, Phil Dowson, Dylan Hartley, Tom Johnson, Courtney Lawes, Joe Marler, Ben Morgan, Tom Palmer, Geoff Parling, Chris Robshaw, Mako Vunipola, Thomas Waldrom, David Wilson, Tom Wood, Tom Youngs.
Backs: Anthony Allen, Chris Ashton, Brad Barritt, Mike Brown, Danny Care, Lee Dickson, Owen Farrell, Toby Flood, Alex Goode, Jonathan Joseph, Ugo Monye, Charlie Sharples, Manusamoa Tuilagi, Jordan Turner-Hall, Ben Youngs.