THE AFL's crackdown on interchange rules has had an effect on two matches at the weekend, with free kicks paid against two clubs for indiscretions.

On Saturday night at Gold Coast Stadium, North Melbourne got a goal after Luke Ball was found to have infringed.

On Sunday afternoon at the MCG, Melbourne benefitted from a mix-up between premiership stars Luke Power and Simon Black.

Although the resultant free kick and shot at goal was missed by Paul Wheatley, it proved a handy behind, with the Demons winning by one point over the Lions.

Lions coach Leigh Matthews was philosophical about the ruling after the match.

“Yeah, maybe the penalty’s too severe but the penalty’s to stop you having 19 blokes on the field,” Matthews said.

“I mean the fact is every player in the competition should know that they can’t go on until their interchange player’s come off, and [there’s] no use being over-anxious and, you know, taking a step forward and taking a step over [the line].

“Everyone knows the rules, so you’d think it should never happen.

“That’s the idea of having a stiff penalty, so it doesn’t happen.”

The AFL overhauled interchange procedures in the wake of Sydney Swans briefly fielding 19 men in a clash against North Melbourne in April. The league has introduced a new interchange holding area in front of the club benches and appointed two interchange stewards to police player turnovers.

A free kick and 50m penalty from the centre is now paid when a team has 19 men on the field, including when a replacement player enters the playing surface before his team mate has crossed the boundary line.

The same penalty is enforced if a player enters the field before his interchange is approved or doesn't go through the appropriate area.

In practice it usually results in a shot at goal from 25m out directly in front.