PLAYERS' union chiefs are urging that the standard players' contract be varied to allow Harry Kewell to sign for Melbourne Victory and boost his earnings by entering into commercial arrangements of his own.

Kewell and Victory have agreed to terms on his personal deal with the club, but a stumbling block is the Socceroo veteran's desire to control his own image rights and to do sponsor deals that could generate revenue for him - something that Football Federation Australia has business concerns about.

Players' union chiefs are urging that the standard players' contract be varied for Harry Kewell. Credit:Reuters

The game's governing body is strapped for cash and is nervous that if the biggest name ever to come to the A-League signed commercial agreements with companies that competed with its own sponsors it could undermine its position when renegotiating those deals or looking for new investors to underpin the competition.

Kewell's management is understood to be seeking to tie up further deals before he signs for Victory that could be argued were existing commercial contracts the FFA would have to honour, as is the provision in the standard player contract.