Fremantle coach Chris Connolly believes running ability will be a key factor in adjusting to rule changes introduced to the AFL this season.

In one change announced during the off-season, defenders will now be allowed to bring the ball back into play after a behind without waiting for the goal umpire to finish waving the flags, possibly resulting in less stoppages and faster movement of the ball.

"It's going to become a real running game with the interpretation of the existing rules and the introduction of the new kicking rule so I think we are all waiting to see how demanding the game's going to be," Connolly said on Wednesday.

"It will end up you need all your defenders being able to kick the ball in on a fast break, but if it's a set shot on goal you take a designated kicker."

"It will be interesting to see how the games pan out."

Connolly highlighted the midfield as an area to improve on in order to take advantage of the rule change.

"Our senior guys will lead the (midfield) charge but there needs to be a lot of talent going through that area," he said.

"We are always trying to strengthen our midfield."