Brown first joined the Highlanders in 2014 as attack coach and masterminded much of the side's flair and enterprise which led it to win the title a year later.
He then took over from Jamie Joseph as Highlanders head coach in 2017, though it was a reluctant acceptance after the franchise struggled to find anyone after Joseph departed.
Brown left at the end of that season to help coach the Japan side with Joseph. He took over as head coach of the Sunwolves side this year.
Both Brown and Joseph are tied to the Japanese team until the World Cup this year and what happens at that tournament will decide the duo's future with the Cherry Blossoms.
Brown's family still lives in Dunedin and he returns to the city as often as possible.
An Otago born and bred player, Brown was very popular in his time with Otago and the Highlanders and is highly rated in coaching circles.
Head coach Aaron Mauger, who signed a three-year deal with the franchise, will still have one year left on his contract in 2020. Mauger has brought a more detailed focus to the side, although it is struggling to make the playoffs this season.
It would be unusual for a head coach to move into a different - and lesser - role but is not unprecedented. Tana Umaga moved from head coach to defence coach with the Blues this season.
The departure of Delaney does not come as a total surprise. His family was supposed to move to New Zealand last year but never did and he spent much of the last off-season back in the United Kingdom.
Highlanders chief executive Roger Clark could not be contacted yesterday.
