John Mitchell has committed his long-term future to England, signing a new two-year contract.
New chief executive Bill Sweeney confirmed defence coach Mitchell has extended his Rugby Football Union (RFU) contract to fall into line with head coach Eddie Jones.
Sweeney admitted it is possible that boss Jones and assistant Mitchell could stay with England beyond their 2021 contracts.
"We have extended John Mitchell's contract through to be consistent with Eddie's, so it goes through to June of 2021," said Sweeney.
"That was in full consultation with Eddie. He and I spoke about it about five, six weeks ago maybe.
"It is part of Eddie's long-term coaching structure plans.
"So we entered into negotiations with John, he is keen to stay and we concluded the agreement about three weeks ago.
"He is contracted now through to June 2021."
Current Wales and 2021 British and Irish Lions coach Warren Gatland has ruled himself "categorically" out of joining England in future.
The search for Jones' long-term successor appears on the back-burner though, as Sweeney insisted the RFU will not confirm England's back-room staff for 2020 until after the autumn's World Cup.
Kiwi defence specialist Mitchell joined England before the 2018 autumn internationals and has now committed his long-term future to Jones' set-up.
Asked if Jones could stay with England beyond the end of his current contract, Sweeney continued: "It is possible, we are not looking at that at this stage.
"The focus now is really on the World Cup and then making sure we get our plans in place post World Cup.
"Eddie has reconfirmed his commitment through to 2021. We have lots of conversations on that and he has said he wants to stay through to the end of that contracted period.
"So from that perspective we've already started conversations around what will the structure and look of that coaching team be coming back from Japan.
"He has got a number of names in the frame. We haven't approached them yet. We wouldn't contract anyone pre World Cup.
"But he has got in mind how he would like to structure that as soon as we get back. We would confirm it immediately as soon as we got back."
Former British Olympic Association (BOA) chief executive Sweeney has joined the RFU in a bid to reverse serious financial troubles suffered by the English game's governing body.
Former chief executive Steve Brown lost his job over hefty cuts that led to scores of job losses.
But now Sweeney has insisted there is "definitely not a crisis" at the RFU, adding: "There's no financial crisis here.
"The similarities with the BOA are there, it's a cyclical business.
"You'd expect to have a loss-making year in the year coming up. It's not a financial crisis.
"The business model at the RFU is inherently very healthy, we generate a lot of cash, a lot of revenue and if you keep your costs in control there's no reason why that should be a fragile business plan. So it's inherently strong.
"Stabilising the financial situation is a key priority.
"It's not in as bad a situation as perhaps I would have expected it to be quite frankly, having read a number of things coming in.
"The team here has done a really good job over the last 18 months already, taking quite a bit of cost out of the operation."