AFL operations chief Mark Evans said on Monday the laws of the game committee had identified two areas for review during the post-season.

"One is holding the ball and giving us a better understanding around prior opportunity, in particular, and illegal disposal. The second main theme that has come up is blocking in marking contests. We will talk to the umpires across that in summer and see where we get to," Evans said.

"I think it's become so well done by defensive groups that it is reasonably discreet. We just want to have a look at it. I am not sure that we will be able to get them all but, certainly, [we will] be able to pick up on more of those blatant ones."

In the laws of the game DVD issued to clubs last season, players were reminded that "where the umpire deems there is an unreasonable or excessive (unduly) push, bump, block or hold that prevents an opposition player from contesting the ball, a free kick shall be awarded against that player".

There was also an example of a block former Tiger Jake King put on Jeremy Howe behind a pack to stop the Melbourne high flyer from launching into a marking contest.

Carey said the umpires faced a difficult task managing any crackdown.

"I think the one that needs [monitoring], in terms of blocking, is when a guy is running to mark the ball, which is what we want to see, and the defender just stands and blocks the run of the player and takes his eye off the ball. It could be four, five, 10 metres off the ball," he said.

"But those types of blocks, it's going to be hard [to monitor] - it happens across the ground all the time."

While Evans spoke of "defensive groups", Carey felt it was forwards who were now more interested in blocking for a teammate.

"There shouldn't be tunnel vision and just saying this is what defenders are doing as a group because I think what defenders do better than ever is guard space and guard an area," he said.

"They are not overly interested in blocking all the time any more. Where forwards are getting smarter, and certainly more team orientated, are at getting over and blocking for someone - a [Jarryd] Roughead will go and block for [Jack] Gunston. They almost take it in turns.

"The one you want to see paid is where they really take their eye off the ball. They have got their back to the play and they just run in and bump a defender, or the defender bumps the forward."

Evans said his operations department was continuing to work on a clearer definition of holding the ball, an issue which frustrated coaches had raised through the season.

Asked on Radio Sport National what his definition was, Evans said: "It is a fairly loose definition, which says that the player has had a reasonable chance to dispose of the ball.

"In umpiring terms, without being absolute on it, it is sort of about four steps - about two seconds with the ball in open space but ... there is something about the player's intent with the ball.

"Sometimes you can look as if you are about to try and burst through a pack. He has no intent to get rid of the ball. He may only take two steps and it just feels like that should be holding the ball. I think that gives us some direction."