If the worst-case scenario becomes a reality, Lamine Yamal's injury could make Barcelona really worried.
The 18-year-old striker could be out for up to a month, which means he will be absent from Spain's World Cup qualifiers against Georgia and Bulgaria next week.
At the same time, this young star also left open the possibility of participating in the El Clasico match against Real Madrid on October 26.
"We don't know exactly when Lamine Yamal will return from this injury. It is difficult to predict because this is not a muscle injury. It could be two, three or four weeks.
We are still not sure if he will be in time for El Clasico. We need to control his playing time and let him recover step by step" - coach Hansi Flick said.
However, behind that is the simmering tension between Barcelona and the Spanish team over the use of Yamal. Flick has criticized Spain for using the young player in the qualifiers in September.
"It's a pity. He was called up in pain, but was still given a chance and had to take painkillers. He played 79 minutes and then 73 minutes, which showed a lack of concern for the players' health.
Spain has good players in all positions, and protecting young talents is very valuable. I am really sad about the current situation, but it seems they are continuing to do so" - the German captain said.

In response, Luis de la Fuente was surprised by his colleague's comment: "I was surprised. He was the national team coach, so I think he will understand and have more sympathy" - said the head coach of La Roja.
Yamal is not the first case of falling into a tug-of-war between the club and the national team.
In the past, Wayne Rooney and Michael Owen - two talents who were early to shine at the age of 18 for the "Three Lions" in major tournaments - were both regulars in the starting lineup for both club and national team. Both later admitted that they had returned to play too early after long injuries, mainly to serve the national team.
As a result, both Owen and Rooney have lost their top form and have parted ways with England at the age of 30. This is a clear warning that Yamal and Barcelona cannot ignore.
Dr. Darren Burgess, former Performance Director of Arsenal and Liverpool, believes that over- exploiting teenagers is a long-term risk.
"Ficsically, having teenagers play with the intensity of competition and training designed for adults will completely increase the risk of abuse injuries.
A seemingly small problem such as recurrent hamstring strain or broken bones due to overload can quickly become a nightmare for the whole career. The biggest price could be losing potential. A player who is exploited too early, not properly protected and developed, can end his career before it really starts" - Darren Burgess said.

Therefore, Barcelona and Spain are shouldering a huge responsibility in protecting Yamal and other young talents. At the age of 18, Yamal is holding a bright future, expected to become a potential successor to Lionel Messi and Cristiano Ronaldo. But that would only have come true if he had not been exhausted by the age of 30.
"If football is really serious about nurturing the next generation, we need to put development first. Only then will today's young talents have the opportunity to become the lasting stars of the future" - Burgess concluded.