Lee Radford has admitted that accepting an assistant coach job with Northampton Saints is a "bit of a left-fielder".
Radford made his name in rugby league and had spells as head coach of Hull FC and Castleford Tigers.
He was contemplating the possibility of a coaching job in Australia's NRL when the chance with Northampton came up.
"Rugby union has always intrigued me, just the size of the sport and its global appeal," 44-year-old Radford told BBC Radio Humberside.
"Just being in and around it this week down in Northampton, the size of the club and the size of the operation in terms of staff and infrastructure has blown me away a little bit."
Radford will focus on the Saints defence when he takes up his new role at Franklin's Gardens as part of director of rugby Phil Dowson's backroom team.
And he has made sure to take plenty of advice from others who have made the same cross-code switch, including England defence coach Kevin Sinfield.
"I've spoken to every man and his dog, every ex-leaguer who's currently in rugby union," Radford said.
"Kev's been one of them, Jamie Langley, Paul Deacon are up in Sale, Martin Gleeson was previously head coach of England attack, Shaun Edwards. It's a natural thing to be done."
Radford had some exposure to the 15-a-side game by playing for Hull RUFC, but his previous chance to move into union coaching with Dallas Jackals in the USA came to nothing because of the Covid pandemic.
"Due to one or two having success early on, it's [switching codes] become more common. There's an awful lot of similarities between the sports - there's a hell of a lot of differences as well, but ultimately the fundamentals are the same in defence," he said.
"Every tackle in union is a competition. Once that ball hits the ground it's an opportunity to get in there and compete for it, whereas in rugby league you're blessed with play the ball. That's a significant difference, I think.
"The fundamentals of how you go into a collision are the same, but the tackle height has obviously got to be lowered significantly [for union]."
The new domestic rugby season will begin in September, with Premiership fixtures due to be released on 18 July.
Saints will be looking to reach the play-offs for the third successive year.