Proposed:

Player can cite irreconcilable differences with their team, and request a trade. In exchange for this request, the player must repay to the team all prorated signing bonus money amortized on the contract, which removes any dead money hit from the team. The team may then trade the player to another team, and the player is required to play out the duration of the remaining contract without renegotiation. Once the contract expires, the player is free to negotiate a new deal as a free agent with that or any other team.

So, you can leave, you just have to pay back a chunk of change and agree to play for (likely) peanuts comparatively when you switch teams. In essence, how bad do you want it?

I don't like that the contracted team has to eat a loss when someone pitches a fit.

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