Most professional clubs expect you to have at least completed your junior rotations before they'll look at you. You're right, most physios do something sport-based if their interested in it (football, athletics, tennis clubs etc all like to have a physio around) but you cant replace the experience you get in hospitals in terms of being a well rounded physio.

My advice? Pursue it as a hobby, do lots of post grad courses like taping, massage etc and find a club who will pay a bit (my current club pays 100 a week, plus i've just started doing some voluntary stuff with a premiership club's academy) and find a nice hospital job if you can. Then when you've done your rotations etc you can start looking for a position with a pro club.

Saying that I've heard of a couple of people who have walked straight into high level professional football, its not totally unheard of, i just think there are better ways