If they have agreed to it in a prior contract it would hardly be unreasonable - in the end it would need to be a an Unreasonable restraint of trade - and as it has been said its all Europe, there are plenty of other clubs to manage a Court may decide to enforce such clauses if they are considered to be reasonable with the reference to the interests of both of the parties and do not breach the public interest in free trade. Id say both of those are satisfied Gotta remember that common law courts love a bargain (contract) and if something is signed usually it holds a hefty amount of weight He had been at the club for a bit and he had known the inner workings and tactics and personalities of certain players and staff - I doubt a court would consider it unreasonable to limit him working in direct competition for a period of 2 years for those things to change.