Payments made by Cronulla to Ben Barba before he defected to rugby union will be included in the Sharks salary cap for the 2017 season.

Fairfax Media understands Barba may have received up to $50,000 from the Sharks before signing a deal to play in the French rugby union competition.

On the day the club trumpeted the re-signing of Australian star Valentine Holmes, they have again been reminded of the cost of Barba's defection to rugby.

The premiers could be forced to forfeit a chunk of this year's salary cap as a result of his decision to walk out on the game, with the NRL set to include any termination payout or advances as part of the cap.