Former Canterbury and All Black prop John Ashworth is the boys' uncle.
Scratch a little deeper and you find Brodie's older brother, Brook, is the Canterbury town first-five this season.
His other cousins Matt and Jason Newton play for North Canterbury and Canterbury Country.
It's Brodie's first year in Super Rugby and he has taken to it like a duck to water.
He is one of three newbies (Ben Tameifuna and Sona Taumalolo are the others) making a name in the Chiefs' engine room and is enjoying his debut season.
"It is going pretty well so far. We've put a lot of emphasis on having a good set piece and we've been dominant there and tracking good so far."
A multi-talented forward he adds height at the lineout, impetus at the breakdown and power at scrum time.
The only thing he admits to not being able to do is "side step", but at 2.04m and 120kg, the youngster is the tallest in the New Zealand conference and one of the biggest in the entire competition, so it's probably not that much of a necessity.
After two years with Hawke's Bay, Brodie has transferred to play ITM Cup for Bay of Plenty this season. Something that will have Steamers fans salivating at the thought of both Retallick boys locking the scrum for the Bay.
"I'm looking forward to playing alongside my cousin at the Bay.
"It was one of my main decisions to move there to go along and play alongside him."
With the two cousins currently playing for different franchises, do they get the chance to give each other a bit of stick?
"We definitely get into each other, especially when we come up to play against each other and definitely on the field there is a little bit extra going on down in the rucks ... It will be a bit different when we're on the same team."
The Chiefs, who currently lead the Super Rugby competition, take on the Reds in Brisbane tomorrow at 6.10pm (NZT).
Chiefs coach Dave Rennie has a near full strength team for the battle against last year's champions, with Liam Messam and Brodie being called back into the squad after being rested last weekend, in their win over the Lions. Alex Bradley comes in at No8 with Kane Thompson, Sam Cane and Robbie Robinson on the bench. Chiefs assistant coach Wayne Smith said the team were expecting a tough encounter against the Reds.
"We know the Reds are starting to hit form with their top players coming back at the right time.
"They have targeted this game on their home track as a must win match for them, so we are expecting an intense fixture," Smith said.
Chiefs: A Taumalolo, M Schwalger, B Tameifuna, C Clarke (captain), B Retallick, L Messam, Tanerau Latimer, A Bradley, B Leonard, A Cruden, A Tikoirotuma, S Williams, R Kahui, L Masaga, A Horrell.
Reserves: H Elliot, T Smith, K Thompson, S Cane, A Pulu, J Willison, R Robinson.
