Barrett will link with the Eels next season on a two-year deal as an NRL assistant after Arthur personally reached out to the former NSW State of Origin playmaker just a week after he was sacked by the Bulldogs in May.

"I rang him straight away and I knew he'd probably want to take a bit of gardening leave there for a while but I just wanted to express my interest," Arthur said on Thursday.

The pair met again two weeks ago and a deal was struck within two days.

Arthur believes Barrett's work in helping transform Cleary from a prodigious talent into a dominant Origin playmaker and premiership winner during two stints at the Panthers, chiefly his second in 2020, is vindication enough of his value as an attack coach.

"He'll take full reins of our attack," Arthur said.

"I think our attack's okay. It's probably just some fine-tuning there and probably working closely with our halves.

"He'll be able to talk to them about his experiences in the game and some leadership stuff and getting the team around the field.

"Obviously you'll have seen the work he's done with Nathan at the Panthers so he can only help in our investment in our two halves and our whole spine."

Barrett's appointment follows Parramatta's loss at the end of last year of Andrew Johns as a playmaker consultant, the halfback legend effectively a victim of COVID-19.

Barrett's signing has also extinguished, for now at least, the prospect of a return to St George Illawarra as an assistant, after he spent the majority of his 295-game playing career at the Dragons.

He was replaced at the Bulldogs by Mick Potter on an interim basis this year, before current Penrith assistant Cameron Ciraldo takes over in 2023.

While he enjoyed success as an assistant with Penrith, Barrett has been unable to match that in the top job, winning just 34 of 107 games as a head coach.

"Trent has a wealth of football experience which he has harnessed over almost three decades as an elite player and coach," Arthur said.

"I'm sure he will contribute significantly to help enhance our football program."

Barrett, of course, won't be of any use to the Eels against Canterbury on Saturday. Nor will Mitch Moses, who's returning from a broken finger, after the Eels failed to score a point in last week's 26-0 drubbing at the hands of South Sydney.

"We just got bashed up through the middle of the field. Our defence was horrible through the middle of the field. We had no physicality. Mitchell's not going to fix that," Arthur said.

"That's got to be addressed with our forwards. If we can fix that up this week, make sure we play physical because that's what it was last time we played the Dogs.

"They came after us physically and we've got to make sure that we're prepared to match that physicality and then that allows Mitchell and Dylan to do their job better."

Australian Associated Press