It is "ludicrous" for the AFL to say there wasn't a crackdown on deliberate rushed behinds last round, North Melbourne coach Brad Scott says.

Fremantle defender Lee Spurr and Brisbane Lion Pearce Hanley last weekend became the first players penalised in 2016 for deliberate rushed behinds after the AFL sent a memo to clubs on the rule's interpretation.

AFL umpires coach Hayden Kennedy said on Monday the free kicks against Spurr and Hanley were not paid because umpires had been instructed to have a greater focus on deliberate rushed behinds.

Kennedy said both adjudications were correct interpretations of the rule governing deliberate rushed behinds, unlike umpiring decisions in the previous two rounds that allowed West Coast's Eric Mackenzie and Port Adelaide's Jack Hombsch to rush behinds without penalty.

However, Scott told reporters on Thursday more free kicks were generally paid under a rule after the League sent a memo about its interpretation.

"At least when you do get a memo you can put your life on it that they're going to pay one," Scott said.

"I would just prefer the umpires coaches said, 'You know what we're going to focus on this week, just the rules, and we’re going to judge every contest in isolation and if we see a free kick that’s there we're going to pay it. We’re not going to be looking for something specifically'."

Scott said the AFL sent out rule memos "a few times during the year", something he would prefer was left to the end of the season.

"There’s a memo that goes out which says, 'This is what we're focusing on', so if you don't want to call it rule of the week, what would you call it?" Scott said.

"Earlier this year it was, 'We're really watching blocking in a marking contest'. So what happens? The blocking in a marking contest free kick count spikes by more than two-and-a-half (times).

"If you tell an umpire this is what we're going to focus on, what do you think he's looking at in the marking contest?

"Is it unfair mid-season on players? They're usually pretty adaptable to rule changes, certainly at the end of the season."