CLUBS will get an answer soon on whether video review technology will be used during the home and away season.

The AFL says it is pleased with how the trial has gone so far in the NAB Cup.

"We're learning through this process," League football operations manager Adrian Anderson said on Monday.

"We've still got to do a bit more work."

Anderson said introduction of a tennis-style challenge system was unlikely.

"The problem with the challenge is the potential for manipulation or (for it) to be used to delay."

But he said he didn't see a problem with umpires listening to players who called immediately for a review. 

"A player can be a valuable indication that there's something worth having a look at, as long as they let the guys do their job once they've made the point," Anderson said.

Of the six referrals in round one of NAB Cup, two saw decisions overturned.

Anderson also said he was surprised by criticism from coaches including Geelong's Chris Scott and St Kilda's Scott Watters about the 'two and two' interchange trial.

Clubs had argued for new ideas to be trialed in the pre-season, and not introduced without being tested.

"It is a bit surprising that you'd tell us to do something like 'If you're thinking about it, trial it', and then say, 'Oh well, what on earth are you trialing it for?'," Anderson said. 

Matt Thompson is a reporter for AFL Media. You can follow him on twitter @MattThompsonAFL