Here's the thing...

1) This was an entirely predictable headline (I have floated this idea on another thread weeks ago, in fact);
2) It's also relatively meaningless. It only impacts us if A) we actually WANT to buy players from within the league and the selling clubs are in a legitimate position to stop us.

Let's assume A is the case, for now. Is B possible? The answer is 'not really'. They could make it difficult short-term, without a doubt. But long-term it's an absolutely idiotic business practice and pretty much impossible in practice.

I've seen it floated on Twitter that NUFC could launch another CAT case to stop this sort of thing, but I'm pretty sure that would go nowhere. No club is obliged to sell us its players, and if they can be obliged then the notion of player contracts would be utterly meaningless. It's not anti-competitive: it's literally part of the nature of a competitive league that a club should be allowed to protect its assets from its rivals.

Where there'd likely be more traction legally is from the perspective of the players themselves. When we were part of the EU, it would potentially be a legal problem for clubs to unreasonably reject demonstrably reasonable transfer approaches - this is partially what led to the Bosman ruling. However, it would be a long and dragged out litigation process to secure players as a result of this sort of challenge, and would be almost entirely pointless from our perspective to rely on it since any current targets would likely be out of contract by the time it was resolved (and, also, I think it would ultimately fail for the same reason as above, not to mention BREXIT).

The main issue is that clubs refusing to do business are cutting off their nose to spite their face: if the players want to move, they simply won't renew their existing contracts, and the clubs will ultimately lose out on a transfer fee (even if the player doesn't ultimately come to us). Telling a player they're not going to be allowed to get a big money move is likely to be massively counter-productive, and player loyalty is more often to other players than it is to a club these days. They're likely to create enormous disharmony within their squad with this approach. So, bring it the **** on, I say. Other teams doing worse over the next few seasons while we slowly build will actually HELP us, rather than harm us.

The other issue is that missing the chance to ship assets at a premium is likely to lead to all sorts of financial difficulties down the line for most clubs. Given FFP, when there's a chance to sell someone who is a squad player (e.g. Donny Van de Beek, Anthony Martial, and these other PL players we've been linked with) for an over-inflated value, it'd be foolish to refuse to do so when you need to continually reinvest in your squad. Very few buying clubs are ever going to be in the position we're in right now i.e. the richest club in the world, in desperate trouble in the league, and also not in any danger of breaching FFP by over-paying for players. This is literally the one time these clubs are likely to have the upper hand in terms of the power dynamic between buyer and seller. If they don't take it, they're going to lose most of these assets to the same club in 6 months' time anyway. If we don't get relegated, we then have a stronger squad and an increased capacity in the transfer market because we didn't pay £25m for a player with 6 months left on his contract.

So, I'm not too worried. I don't think clubs will do business with us, but I also think that'll come back to haunt them.