Essendon and Port Adelaide are predictably at odds over what it might take for Patrick Ryder to change AFL clubs.

Ryder is disgruntled because of the Bombers’ long-running supplements scandal and wants a trade to the Power.

The ruck-forward would be a massive loss for Essendon and has two years left on his current contract.

But Ryder could exercise a clause in the standard player’s contract and try to leave Essendon, saying they had breached their duty of care.

Port list manager Jason Cripps said on Friday that Essendon had knocked back their initial offer of a round-one draft pick for Ryder.

Port’s current top pick in the November draft is No.16.

“There’s every chance it (negotiating with Essendon) will be drawn out,” Cripps told SEN.

“He’s obviously contracted and we’re very respectful and mindful of that being the case.

“We’ve had some discussions with Essendon – we’ll continue to do so to hopefully broker a deal that’s fair for all parties.

“At this stage they’ve knocked that (the offer of a first-round pick) back and we’ll continue to work through with them in terms of what they’re actually hoping to get.”

Cripps also floated the idea of involving a third club in the Ryder deal.

Ryder will be one of the key subjects when trade period starts on Monday.

The trade period ends on Thursday, October 16.