Inducing breach of contract.

I don't think Sale would get away with playing dumb and pretending they didn't know he was contracted to Cas.

The problem they have is that if Cas haven't accepted his retirement/resignation, he is still contracted to Cas right now,

Officially, he might not be. A contract is between the employer and the employee. If he considers himself not to be employed by Castleford then he isn't.
All Castleford can do is make a claim against him for their financial loss and move on.

They're not going to pretend they didn't know he was contracted, they've reportedly made an offer to Cas for him. They will claim that when they were rejected by Cas they only spoke to Solomona to gauge his thoughts on signing for Sale when his contract ran out with Castleford, then anything he has done has been of his own decision. Added to that the fact they're claiming they haven't offered him a contract and that several RU clubs are looking to sign him and it's near impossible to lay any blame on Sale for this. As to Solomona, if Cas have rejected his retirement then they will need to continue paying him unless it explicitly states in his contract that they can stop his wage... If it doesn't and they have stopped it then Solomona could take Castleford to an ET for withholding his wage

It's probably going to end up as an out of court settlement, where Sale give Solomona a "signing fee" which he is instructed to give to Castleford as a means of buying himself out of his contract. The payment will be for an "undisclosed sum" with Castleford saying that they have mutually accepted Solomona's retirement from Rugby League and will be retaining his League Registration for the remained of his contract with them.

Other than this, it has implications far beyond our little sports, where if players are able to break contract then clubs will also be able to break contracts with players without financial implications who are injured/under performing. This won't just be for rugby but will stretch to all sports as the case will be cited when/if a player tries to take a club to court. It's a dangerous game which has the possibility to effectively make all sports contracts null and void

He can't just decide to end that contract.

Yes he can. It's a breach of contract, and he becomes liable for any financial loss to the employer, but the days of forced labour ended decades ago.

Except they know he is contracted to Castleford and are making him an offer.

If Sale know that Solomona has a contract with Cas. Then they know they cannot discuss one with him. If Solomona decides to retire, he still needs to be released from his contract with Cas. He doesn't get to say the word retirement and all his obligations disappear. He is still under contract.


It wouldn't just be sports, it would be huge amounts of people in huge amounts of jobs.

Not so. If Solomona has committed the repudiatory (first fundamental) breach of contract, Castleford are entitled to dismiss him and pursue him for the financial loss caused by his repudiatiry breach.

How can you breach a contract which has ended? You can't.

He must satisfy that contract in one way or another, which could be financial recompense.

Because in this case, the ending is the breach. The day he didn't report to work and informed Castleford he did not intend to do so, he breached his contract and it therefore ended.
He should know that Castleford may seek to gain financial recompense, which is what seems to be happening. Unfortunately, I suspect his agent failed to mention the fact Castleford may pursue him personally.

The ending is not the breach, and nor is it reasonable to assume the breach is the ending.

The breach is not reporting to work. Not reporting to work whilst breaching the contract, does not end it. Solomona could turn up to work tomorrow and rightly assume that he could carry on with his contract (Cas could at anytime end that contract if they perceive his time spent AWOL to be gross misconduct, but would still need to follow the process for ending that contract as set down in it)

I was thinking more of this case in particular, assuming what is suspected is true.
Given what we 'know', Solomona's contract did end when he failed to report for work and told Castleford he didn't intend to do so. He didn't consider himself to be employed by Castleford (and therefore his contract has ended) so there is no requirement for Castleford as the (previous) employer to follow any procedures at all because he is no longer an employee.

Put simply though, the fact seems to be that he has committed the repuditory breach of contract at some point. Castleford are entitled to seek compensation for their financial loss.