Personally I dont see how many MLB players could be using HGH. On 2iu's a day with a 5/2 split of taking it, my hands are swollen to the point where I would hate to grip a bat or throw a baseball.
The biggest binifit I can see so far is an increase in my appatite and I am starting to see a small loss in body fat. The loss is prolly combined with a more strict diet in the past month.
IMO for guys in pro sports there is different and better things I would take.