There is no magic formula for developing special players...
...but recent scientific research* does provide some very interesting insights:
Talent is not ‘innate’. Messi (or any other outstanding performer in sports, science or art) didn’t receive or inherit special ‘genes’ from birth
Every world class performer has a history of many years of deep practice that started at a young age
A condition for many years of deep practice is intrinsic and sustained motivation, a characteristic all top performers share. No top performer has ever circumvented these rules!
If talent is not innate and excellence is the result of many years of sustained deep practice does that mean that anyone can become a top level player? Theoretically yes but the quality of practice is one of the most important factors.
* Coyle; Ericsson, Gladwell; Syed et al