THE NEW rule on players sliding into contests will lead to more head clashes, Hawthorn captain Luke Hodge says.

And he is concerned that it may also make players less desperate to win the ball in ground contests.

Hodge told he had seen players stop and prop during the NAB Cup, uncertain about whether to go in for the ball or not.

"[In] the first couple of games of the NAB Cup you could see that players were unsure," he said.

"Do they go in and get the ball as you have been taught since you were five or six, or do you stand back and let someone else do it and then you get a free kick because they make contact below the knees?"

With players determined to keep their feet, Hodge says there may also be an unintended consequence.

"[There are] going to be more head clashes," he said.

"Hopefully it doesn't affect the game too much or change too much about it."

Meanwhile, Gold Coast captain Gary Ablett said players remained confused about the new rule.

While supportive of its intent to reduce leg injuries, he said some players were still uncertain what to do when contesting the ball.

Ablett said there had been occasions in the pre-season where a player had been penalised for making forceful contact below the knees of an opponent in a contest that would have drawn a high contact free in previous years.

"The AFL has to understand that players have been playing that way for a long time and it is not just easy for them to change those techniques," he said.

"It is one of those things that the players will have to learn to adapt to."

The new rule not only prevents players sliding in feet first – a change that players support – but also penalises a player making forceful contact below the knees.

The rule does not apply if players are smothering with their hands or arms.

The AFL is prepared to ride out the adjustment period and initial confusion to protect player safety.