Former Spain coach Javier Clemente has called on football's medical experts to speak up about the playing of youth players in senior football.
He said on La Tribu: "Yamal, at only 16 years old, plays a lot. He has to go at a faster game speed than he should to stand out.
“He has to make more effort than many of his rivals and when he goes to the crash, I won't even tell you. That happened to Ansu Fati. He collided with a 28-year-old guy and blew his knee off. The legs, the bones, the ligaments, the lungs... everything requires preparation. It is not the same at 27 or 23 as it is at 16. The kids are good and well trained, but they have to go to much lesser efforts."
Clemente continued: "I would like the doctors to speak, but they are employees of the club and they will not open their mouths.
"Perhaps, the day they are allowed to give their opinion on this, they will say that they do blood tests every now and then, that they look at their heart, kidney, liver and gallbladder and that they are great, that they control everything and 'They are great'.
"But what they do not tell or it is not known if they do is the rest of their training.
"What they should control and tell us is to analyze the difference in effort from playing a certain number of games in the youth team, which takes them very well, to playing with professionals, or a national team match, or even a Champions League final , as many have played it. That's what you have to ask the doctors. Hey, doctor, do you think we are going with enough guarantees with this boy?"