Barcelona changed Messi’s life when they signed him because they helped him to overcome GHD. Human growth disorder could have prevented him from achieving his legendary career. They saw the undersized youngster’s potential and agreed to support his treatment. He took human growth hormone to build an average physique.
It should be noted that Messi and Barcelona received La Liga’s approval before they went down this road. They didn’t break any rules and Messi’s current physique proves he doesn’t have any abnormalities. But he was barely over four feet when they brought him to Camp Nou (via Bleacher Report).