Clearly Brook from this list.
But I expect them all to lose, with Brook having the biggest chance of pulling the upset.
I think this tells the story;
Adrien Broner (1/33)Draw (40)Gavin Rees (16)
Sergio Gabriel Martinez (1/7) Draw (35) Martin Murray (6)
Kell Brook (13/8 )Draw (25)Devon Alexander (4/6)
I see someone already put up the odds