Trent Robinson admits he was not surprised to see Roger Tuivasa-Sheck make the switch to rugby union, believing the fullback had an itch to scratch in the 15-man game.
Robinson is likely to come across Tuivasa-Sheck on an NRL field for the final time on Sunday, with the Warriors only drawn to play the Sydney Roosters once this year.
The pair's relationship dates back to their 2013 premiership success, when Tuivasa-Sheck was aged 20 and Robinson was a rookie NRL coach at the Roosters.
The Kiwi spent three years under Robinson at the Roosters, including his record-breaking 2015 season where he averaged 214 metres at fullback before heading to the Warriors.
The 27-year-old is now determined to crack it in union, set to start with Auckland next year in Super Rugby and eying a spot in the All Blacks' squad.
"It's exciting for Roger. He's a driven guy who has done a lot in our game," Roosters coach Robinson said.
"He came across and had to learn the game of rugby league. He was definitely a rugby union player when he came across.
"He's obviously got that itch he needs to scratch to go and play rugby union and see what he can do at the highest level."
Sunday's match shapes as a battle of the No.1s.
Tuivasa-Sheck was superb in last week's win over Canberra, busting nine tackles and topping 200 metres with ball in hand to be the Warriors' best.
Beyond that, his try-saver on Jordan Rapana won the game for the visitors, with the Warriors captain having spoken about his increased desire knowing he is leaving the club.
Meanwhile James Tedesco remains the competition's best player, and has scored six tries in the first three rounds.
How he adapts to life without Luke Keary will be crucial in the Roosters' season, with the pair one of the NRL's most lethal combinations before Keary's season-ending injury.
There had been some thought that the fullback would have to play more of a play-making five-eighth role at the Roosters in Keary's absence.
But Robinson insisted that would not be the case.
"It (Tedesco's game) doesn't change," Robinson said.
"His ability to go out there and play his natural game is really key."