Real Madrid will be without Rodrygo Goes until 2027 in the worst case scenario, with the Brazilian expected to be out for most of next year.
He was diagnosed with the injury on Tuesday, and his meniscus has also been affected, extending the period he will be out.
It was a heavy blow for the 25-year-old, who has been ruled out of a second World Cup appearance as a result.
Reports say Rodrygo picked up the injury in the 66th minute against Getafe, but played until the end of the match, with the injury not being noticed.
After the injury was confirmed, Rodrygo posted on Instagram, saying that 'life has been a bit wild with me lately'.
The Brazilian was struggling with mental health issues towards the end of last season, and was sidelined for a month.
“Even without realizing it, I believe… One of the worst days of my life, how much I fear this injury… maybe life has been a little cruel to me lately… I don't know if I deserve this, but what can I complain about? How many wonderful things I've already experienced, that I didn't even deserve.”
"A big obstacle has arisen in my life, in my career, and it prevents me from doing what I love most for a while. I'm out for the rest of the season with my club and out of the World Cup with my country, a dream that everyone knows how much it means to me. And all I can do is be strong as always, this is nothing new."
"Thank you all for the prayers, messages and love! You mean so much to me. Even though this is a very difficult time, I promise not to stop here, I believe I still have many incredible things to experience and bring joy to all those who believe in me, it's just a see you soon... God remains in control of everything."
However, the risk of a major anterior cruciate ligament injury is something Rodrygo has been playing with for the better part of three years, according to The Athletic.
They say that in the summer of 2023, he was diagnosed with a partial ACL tear after international duty with Brazil. It was decided not to have surgery, and instead to pursue 'conservative treatment'.
It is an injury that carries the risk of a bigger problem, as it happened, but can be treated without surgery, through preventative work and physiotherapy. There is no suggestion that the decision was not the right one, and his spokesman Fernando Torres commented that the 'most appropriate solutions' have always been chosen.
However, there are concerns at Real Madrid about the club's medical department. Former nutritionist Itziar Gonzalez de Arriba has publicly criticised the club's treatment of players, and Kylian Mbappe recently travelled to France for a second opinion on his knee injury. Rodrygo's injury is the sixth ACL tear Real Madrid have suffered in less than three years./Express newspaper/