Wiliame last played in the NRL with Manly in 2016 but proved one of the premier backs in the Super League in three seasons with Catalans.

He had established pair Tim Lafai and Euan Aitken in his path on returning to Australia with the Dragons, but McGregor said he did enough to unseat the latter.

"I think he was out best trialist," McGregor said.

"He made three clean line breaks against Newcastle, he had probably three or four really good touches against Souths. He was good in the Nines and his training's been really good.

"It was a tough call, Euan didn't do a lot wrong, I just thought Brayden was bringing something different to our footy team for round one and he deserved the opportunity.

"He's coming off a really big year in Super League, he was one of the form players over there, he's at the right age and he's really got confidence in his game."

The move has seen Lafai shift to the right edge after spending his time with the Dragons exclusively on the left. It's a significant shift but McGregor says it won't be an issue for the 28-year-old who played at right centre with former club Canterbury.

"Laf played all his footy at Canterbury on the right," McGregor said.

"Josh Morris was left centre, so he's played five or six years on the right and played in a side that made it all the way to the grand final as right centre."