But the family connection with the Greytown squad goes beyond the four Isaacs. Their uncle, Mana Fairamo, is in the front row and their cousin, Mana's son Joshua, has been a regular among the loose forwards.
Nobody understands better the huge influence the Isaac brothers have had on Greytown's fortunes in 2012 than coach Ritchie Robertson, who labels them as a "very important" part of the team unit, on and off the field.
"You know what you are going to get from them, they always give 100 per cent," Robertson said.
"And they've all got plenty of natural talent, you could play them in any position and they'd give it a decent shot."
As for the brothers, Tavita Isaac is quick to emphasise while they enjoy each other's company, and are never shy to offer opinions at game's end on how each of them had performed, they were simply four of a group of players all determined to do Greytown proud.
"When it comes right down to it, the whole team are one big family, no one player is more important than the others," he said.
"Actually, it's like having 15 brothers out there, we're all in it together."
The Greytown v Gladstone semifinal will kick off at Greytown at 2.30pm, the same time as the other semi which will feature Martinborough and East Coast at Martinborough.
The curtain-raiser match at Greytown will feature the Kuranui College first XV.
