THE DEBATE over the centre square at the Gabba kicked into another gear on Monday after Brisbane Lions coach Leigh Matthews hinted that the AFL knew the rock hard surface was unfit to play on.

Matthews maintained the rage after it emerged Lions midfielder Scott Harding was considering suing for damages over the Gabba surface.

Harding suffered a knee injury and missed four matches after being slammed into the centre square in an AFL clash last month.

Asked if he thought the surface met AFL guidelines, Matthews said: "Therein lies the problem - what if it didn't?

"If the AFL said ‘this doesn't meet our guidelines’, what would happen? Where do you play the game?

"You've got a firm surface or a ground that you can't play on. That's a bigger problem, isn't it?

"You've got problems, or you've got real problems."

AFL media relations manager Patrick Keane dismissed any suggestion that the Gabba surface was too hard.

"The surface is inspected before every game and the Gabba falls within our safety guidelines," Keane said.

"It would have been inspected again before Saturday's game (against the West Coast)."

Harding isn't the first player to blame the pitch for causing injuries.

Earlier this month Brownlow Medallist Simon Black said the pitch could even cut short his career.

Matthews has been an outspoken critic since his first season in Brisbane in 1999.

While he claims to have "nothing to do" with Harding's mooted legal action, Matthews said he wasn't surprised.

"A player eventually will get damaged and seek retribution," he said.

However, Matthews said a sighting of an AFL Players' Association representative at the Lions headquarters on Monday had nothing to do with Harding.

Besides, Matthews said the players' association was well aware of the surface.

"You don't need to look at it. We already know what it's like," he said.

"That's the thing that amazes me. Everyone knows what it's like.

"I've got no beef with the curator because the curator is working with sub-standard materials for a football surface.

"We're tenants and we have put forward over the years that we would like a normal turf surface over the whole field, rather than a rock hard centre wicket block.

"It's either hard or rock hard. That's a fact. How many times can you say it?