They probably can't apply themselves because they can't. I was a decent amateur tennis player but an injury took the edge off my game. They was no way to restore it so I stopped playing. These players didn't choose to get injured, so are entitled to what their contracts say they are entitled to, and when those contracts expire it is time for a civilised mutual consideration of the future. If a soldier returns from a war suffering from injury, surely you wouldn't tell him to pull his socks up and get back in their or else not get paid entitlements.