NORTH MELBOURNE captain Adam Simpson has called the circumstances that led to last week's draw — when Sydney had 19 players on the ground but was not pulled up by the Kangaroos — a "costly mistake", but has defended his club's handling of the issue.

Simpson said his club was right not to call for a head count of Sydney's players, even though it knew it had an extra man on the field in the dying stages of the game.

"It would have been a pretty big blow-up if we had've done that," Simpson said, speaking at Tullamarine yesterday ahead of his trip to Adelaide to take on the Crows tonight.

Under the present rules, only the captain of the opposition team can call for the head count, although the league has indicated that it will change that rule to avoid a situation like last week's occurring again.

"It was a mistake. A costly mistake, I suppose, from our point of view, but look, a week's so long, now we've got to concentrate on Adelaide," Simpson said.

But he did have one lasting regret from that final passage of play.

"Looking at the play, actually I probably should have taken the mark," he said of the failed attempt to grab the ball from a Michael Firrito kick-in that resulted in a turnover to Sydney and, ultimately, the point by Brett Kirk that drew the game.

"I kept seeing it on TV and thinking, 'Geez, I should have taken that grab'."

Hawthorn coach Alastair Clarkson believed the AFL's more stringent interchange rules — including an extra interchange steward at each of this weekend's matches — was the "right way to go". Clarkson's side accidentally fielded an extra man during a pre-season match this year.

The AFL's crackdown comes after it fined the Swans $50,000 ($25,000 suspended) for having an extra man on the field against the Kangaroos.

Clarkson said Hawthorn had been more focused on monitoring its rotations after the club was fined $7500 for having too many players on the ground during the pre-season competition. Brent Guerra was a 19th man for about four minutes during a pre-season cup semi-final against Adelaide in March.

Clarkson yesterday supported the AFL's move to tighten interchange rules, but said it would not affect his team as the Hawks had already become more diligent after Guerra's gaffe, which Clarkson described as a "simple mistake".

"I think it is the right way for the AFL to go," Clarkson said. "Since our fiasco with the (semi) final over in Adelaide, where we ran an extra bloke onto the ground as well — which was just a simple mistake — we have been trying to be as diligent as we possibly can. We don't want to endure any sort of fines."

He said the rules could affect clubs with high rotations, including today's opponent Collingwood, one of the highest rotating clubs in the league.

"We also aren't as heavily a rotating side as some of the other clubs in the competition. I would imagine for some of the teams that rotate as heavily as say a Collingwood, for instance, the greater frequency of interchange, the more likely there is to be some sort of error throughout the course of a game," Clarkson said.

"But, from what I can gather, Collingwood have done it really, really well and I think as long as you're diligent and well-structured and well-organised on the bench, those sort of things should really be an aberration."

Clarkson was quick to dismiss criticism of captain Sam Mitchell and vice-captain Luke Hodge after reported allegations the pair had tried to cork opponents' legs during matches. He said the club has not received a formal complaint and the issue was "dead and buried".

"We have got fierce competitors and that is the way we like our players to approach the game. There's been no official complaint, so there's no issue from our point of view. The issue died for us (on Thursday)."