hey genius, have you done much calisthenic training?
I have about 20 years of body building experience ( yeah, that's what weight lifting was when I was doing it), about 5 years of Capoeira, and another 4 of rock climbing. I tell you at 45 yrs old I'm still quite strong with out the use of weights.
here's a quick leg workout for the soccer player you mentioned:
20 pistols each leg
20 box jumps 36"
20 step ups 36"
20 side lunges each side
50 yard sprints
tailor the rounds and effort to the individual.