If you're Chelsea, you take a £25m punt on an injury prone player.for 25m its not the end of the world if it doesnt work. 25m is peanuts in football today. its a punt worth taking, if it dont work, oh well.
If they're crap, you just farm them out to the u23s and give their squad space to someone else.
If you're Spurs, you don't. You don't discard a £25m "asset" you keep them in the 25 man squad no matter what as we can't have a £25m asset that isn't able to ever play.
And by doing that, you block anyone else from joining the squad.
Levynomics.
Init.