Jason Ryles will make a shock return to the rugby union coaching ranks as an assistant with the Wallabies at next month's World Cup in France.

Wallabies coach Eddie Jones needed to replace attack coach Brad Davis, who surprisingly quit the squad for "family reasons" just before their departure from Australia.

Ryles was a skills coach with England under Jones but cut short his contract in 2021 after six months as he was working remotely, unable to relocate to the UK due to the coronavirus travel restrictions.

The 44-year-old hasn't worked as an attack coach, however Davis had similar credentials with Jones saying he was overseeing the program.

Before joining England Ryles worked with the Melbourne Storm and has signed a deal to rejoin the NRL club in November, knocking back the head coach role at St George Illawarra to do so.

As an assistant there he helped them to a premiership success in 2017 and two other grand final appearances, while he also played over 200 games in the NRL and for the Kangaroos.

After returning from England Ryles linked with the Sydney Roosters in 2022, but was axed midway through the current season with the club unhappy he was pursuing a senior coaching role.

Before the team's flight from Sydney on Thursday Jones said he was already in discussions about a replacement for Davis and vowed to "improve the coaching staff".

"Jason is the most sought-after coach in the NRL. He will add immensely to our coaching staff and help prepare the players to win the Rugby World Cup," Jones said in a statement on Friday.

"We are thrilled to have him join the team."

The Wallabies have another former NRL player in their coaching ranks, with Brett Hodgson in the defence coach role.