Saracens' Paul Gustard is to join the England Saxons coaching team ahead of January's clashes with Ireland Wolfhounds and Scotland A.
Nick Walshe and Ian Peel have also been reappointed to lead the England U20 programme during the Six Nations as well as the defence of their IRB Junior World Championship title in New Zealand in 2014.
Gustard filled the defence coach role on England's tour to Argentina in June, and is being seconded to the Saxons programme from his Premiership club.
He joins head coach Jon Callard and forwards coach Simon Hardy in the Saxons management team led by the RFU's Head of International Player Development Joe Lydon.
"Paul Gustard will join the Saxons coaching team for January's internationals and we're grateful to Saracens for releasing him to us," said Lydon.
"Having him on board adds real value to our programme for two important matches, in terms of both continuity from the summer and in closer integration with Premiership clubs, players and coaches.
"It's also good to confirm that Nick Walshe and Ian Peel will continue developing the Under 20 group throughout the Six Nations and then take side to New Zealand next year where we're defending our world title.
"They helped lead England to success in France last time - aided by Jon Callard and Simon Hardy - and the tournament win was the culmination of a huge effort from all of the management staff and players combined. We know that, like the Saxons, the Under 20s is a key component in the international player development pathway."
England head coach Stuart Lancaster was also pleased by the appointment and confirmation Walshe and Peel will resume their U20 roles.
"Having worked with Paul Gustard last summer I know the energy and expertise he will bring to his role with the Saxons and I'm looking forward to see Nick Walshe and Ian Peel build on their success this year," said Lancaster.
Gustard added that he believed the national side's tour of Argentina in June, where a number of inexperienced Test players were blooded and developed, was testament to the array of talent at the fringes of English rugby.
"The June tour to Argentina suggested English rugby is producing an exciting generation of talented players, and it will be a privilege for me to continue working with many of these players when the Saxons gather at the end of January. I am grateful to the RFU and Saracens for creating this opportunity and I'm looking forward to working and sharing ideas with Joe, Jon and Simon," said Gustard.