In my opinion, (and I know it's likely very Naive), It wouldn't hurt any of these players to extend their deals to protect the club that has not only provided a platform and playing system for them to shine in, and become sought after commodities, but has also paid them well beyond what the club could realistically afford, almost to bankruptcy.
Why can't they just show some minor appreciation for the club and it's long suffering fans by extending by a year, so the club gets a fair return when they leave. Will they even notice any impact on future earnings?
I'll tell you why.
They're being Selfish and Greedy!
A bit of loyalty and support for the club that's made them shine wouldn't hurt.