The Illawarra Steelers and St George Dragons junior representative sides begin the first of their official pre-season trials at WIN Stadium on Saturday.

While the emphasis of both the Harold Matthews Cup and SG Ball matches is usually firmly fixed on the players, this season's annual fixture is likely to have more focus on the men calling the shots.

Former Dragons teammates Dean Young (Steelers SG Ball coach) and Ben Hornby (Dragons SG Ball coach) will be pitted against one another for the first time since retiring at the end of last season.

Dragons junior high performance unit coach Ben Haran admitted much of the spotlight would be turned to how the former NRL stars performed in their new roles.

"Whilst the trial is about the players, and what they can and cannot do, and not the coaches, I'm sure there will be more than just a passing jibe between Dean and Ben on the day," he said.

"They've always been competitive, and I don't think either one will let the opportunity pass if there is a chance to exchange a friendly word on Saturday."

The SG Ball hit-out will kick-off at 5.15pm on Saturday.

At 4pm, the Illawarra Steelers Harold Matthews Cup (U16s) teams take on their St George counterparts. Entry is free.