He's the manager. He has already cited 'footballing reasons' - that's enough. He doesn't have to persuade Rio that he has made the correct decision.
(To the footballing reasons we can now add 'attitude problems - unable to accept authority of the manager').
But, which ever way you look at it Hodgson is managing this situation very very badly. The "football reasons" line is hard to believe and looks very exposed. I had hoped that Hodgson's appointment was going to bring an end to these unnecessary needless side-shows which always follow the England team into tournaments. Sadly it isn't the case.