Has it not been reported that if Henderson returns permanently to the UK at any time in the next (three) years, that he owes HMRC £12m for tax payable on his earnings in Saudi - and that as such, a return to the UK is unworkable?
(No idea about their contract situations, but) Ashley Young, Jonny Evans, Craig Dawson, Danny Ings, Alex Oxlade-Chamberlain, Seamus Coleman, Ben Davies....
If not British, then maybe Tiago, Hojberg, Jorginho, Firmino?