You really don't understand contract law, do you? The contract that Silva has to fulfil is his contract to manage; that is not a monetary item. The contract Watford have to fulfil is to pay his salary. If you were a builder and I contract with you to build me a house, you have to get the house built. You could say 'look, if I pay you the money that you would have paid me even though you haven't paid me anything except the deposit, can I be let off building your house?' I would probably say fair enough, because I would be quids in and would effectively get my house built (by somebody else) for free. However if I was desperate for somewhere to live and there were no decent house builders except for you, I would say sorry pal, get it built. If you downed tools I would take legal action for you to fulfil your contract and I would certainly apply for and get an injunction stopping you from building another house.