Kiwi coaching great Wayne Smith has sent a warning to the yet-to-be-selected All Blacks coach about new Wallabies coach Dave Rennie.

Smith worked alongside Rennie as an assistant and mentor at the Chiefs from 2012 to 2014, helping turn a side which finished bottom of the New Zealand conference in 2011 claim back-to-back Super Rugby titles in 2012 and 2013.

Now the former All Blacks assistant coach is warning Rennie could do the same for the Wallabies after their quarter-final exit from this year's World Cup under departing coach Michael Cheika.

Smith said Dave Rennie will be relentless in his pursuit of excellence and he will take no prisoners.

Rennie will become the Wallabies' second non-Australian coach, following countryman Robbie Deans who led the side from 2008 to 2013.

[Source: TVNZ]