Tupou's Super move solidifies Wallabies' pack

Taniela Tupou will remain in Australian rugby union but switch states, while fellow prop Angus Bell's contract extension at NSW is a further boost to the Wallabies' front-row stocks.

The future-proofing moves came as Wallabies assistants Dan McKellar and Petrus du Plessis resigned from their roles on Wednesday.

Queensland Reds powerhouse Tupou has told his teammates he will leave for the Melbourne Rebels next season, the prop recovering from an Achilles tear and unlikely to feature in Super Rugby Pacific until then.

Tupou arrived at Ballymore as a teenager with a viral YouTube highlights reel but will depart as a 26-year-old father, just shy of 100 caps and among the club's top-five tryscorers.

AAP understands there are no sour grapes at the Reds, who were aware Tongan-born Tupou sought a change of scenery after nine years in Brisbane.

He had been interested in a move overseas before the injury, while a recent change in management reinvigorated the prospect of a domestic move that's expected to be confirmed imminently.

Tupou is targeting a return in time for the World Cup in September but - under current Rugby Australia selection rules - his shift to the Rebels means Wallabies coach Eddie Jones won't need to use one of his overseas picks to call on the game-breaking prop beyond that.

The deal, reported to be a two-year contract, comes after fellow props Allan Alaalatoa (Brumbies) and Bell (Waratahs) signed deals with Rugby Australia seeing them through to the home World Cup in 2027.

Alaalatoa is a captaincy option under the new Jones era while Bell, 22, has already played 20 Tests and is highly-rated by the returning coach.

Meanwhile Wallabies forwards coach McKellar has stood down, the former Brumbies coach set to take over English Premiership club Leicester, replacing new England mentor Steve Borthwick.

Borthwick has taken over from the sacked Jones, who was keen to retain McKellar's services in a World Cup year.

"This was an extremely difficult decision to make but it's one that's made with my best professional and family interests in mind," McKellar said in a statement.

"I firmly believe my next challenge will make me a better coach and hopefully allow me to return home and contribute in a positive fashion to Australian rugby in the future."

After meeting with Jones, scrum coach Du Plessis also stood down and says he'll pursue business interests outside of rugby.