Going to the States is like semi-retirement really, isn't it ?
I expect this is his last big payday before he ends up in the lower leagues or becomes a painter and decorator or something.
Clearly he was being played above his ceiling for quite a few seasons now and never really broke through anywhere. Rather than accept that and try to work hard in the lower leagues and become better, I suspect that he has used his reputation as a PL player to milk a bit more money out of the game with minimum effort.
Bye bye career after that, I reckon.
Maybe he has been shrewd with his money and can afford to retire after this contract expires. I have my doubts though !