THE AFL has moved to prevent the sport going down the same path as rugby league, tightening its rules on players signing with a new club and warning clubs they risk $100,000 fines if they break the new rules.

Under the previous rules, clubs were banned from reaching a binding agreement with a player before he had finished the season with his existing team.

But clubs could make contract offers in advance, in the 'off-season window' before the start of the last year of their contract.

[ Related: Full list of player rule changes ]

The new rules state that players can no longer be signed during that window, and that "any discussions concerning potential contracts occurring during the season must be specified as non-binding".

Clubs caught breaking the new rules can be fined up to $100,000.

AFL football operations manager Adrian Anderson said the rule change had come about following consultation with the football industry.

"Free agency will place a new test on the rule which prevents clubs from signing opposition players during the course of the season," he said.

"This rule has served the competition well over the years by ensuring the AFL has avoided the situation which occurs in some other sporting codes where someone plays out a season for a club having already signed with another club for the following year."

[ Related: Full list of free agents ]

No AFL player has admitted to signing with a rival team in advance, although former Adelaide defender Phil Davis announced he intended to negotiate with Greater Western Sydney while still a Crow.

There was also heavy speculation over whether Gold Coast's Gary Ablett, the Giants' Tom Scully and others had signed with their expansion teams a year ahead, although both maintained throughout their final seasons with their first clubs that they were yet to make up their minds