THE AFL will trial rule changes in the VFL for the third straight week on Saturday, with a new tweak added to the mix.

In addition to the now-familiar 6-6-6 starting positions at centre bounces and enlarged 18m goalsquares, all boundary throw-ins inside the 50m arcs will be brought in five metres from the boundary line.

The Northern Blues will again be involved in the trial when they host Sandringham at Preston City Oval from 2pm.

The Blues' game with Coburg last week featured first two subtle tweaks, a week after Coburg became the first team to trial those two rule changes when it played Werribee.

MINIMAL IMPACT Second rules trial goes off without a hitch

Northern Blues coach Josh Fraser said after last Saturday's game, which his side won by 16 points, that the rule changes had little impact on the way the match was played.

"To be really honest, I don't feel like it changed the game a lot," he said.

"I actually like the 6-6-6 (starting positions), just from an aesthetics point of view. It gives the game a good feel. Kick-outs are longer and down the middle.

"(But) once the ball is bounced … you can make your way with pressure and numbers as you would."