Travis Kelce warns Louis Rees-Zammit his move to Kansas City will be 'HUMBLING' early on as he swaps rugby for football... but brother Jason believes he has potential to be 'the most marketable player of ALL TIME'

Rees-Zammit, a former rugby star for Wales, put pen to paper on a three-year deal with the Super Bowl champions last month after making a shock switch to football.