1. Luca Toni (Bayern Munich)
Luca Toni was a key player for Bayern Munich even before Van Gaal arrived in 2009, but this didn't impress the coach at all. The conflict began when Van Gaal noticed Toni dressed casually at a dinner, and he harshly reprimanded the player. Needless to say, the 2006 World Cup champion with Italy was uncomfortable with this treatment. Toni later remarked, "Van Gaal doesn’t know how to treat key players properly."

2. Robin Van Persie (Manchester United)
Van Persie and Van Gaal shared an emotional celebration after the Netherlands' 5-1 victory over Spain in the 2014 World Cup, but their relationship quickly deteriorated just six months later at Manchester United. Van Persie expressed a desire to drop to the reserves to get more playing time. While such a request might usually please a coach, Van Gaal responded by benching Van Persie, which significantly altered their dynamic.

3. Zlatan Ibrahimovic (Ajax Amsterdam)
Ibrahimovic has maintained a hostile attitude toward Van Gaal since 2004, when the Dutch coach insisted that the Swedish star should only play in the Champions League when the team had no chance of progressing. In his autobiography, Ibrahimovic even called Van Gaal a "loud empty barrel," and revealed that a heated debate broke out between Van Gaal and coach Ronald Koeman over his performance.

4. Franck Ribery (Bayern Munich)
Franck Ribery and Van Gaal worked together to lead Bayern Munich to a domestic double and reach the 2009/10 Champions League final, but their relationship was far from smooth. Ribery shared his thoughts on Van Gaal, saying, "We have different outlooks on life. When he starts something, no one knows what will happen. He cares for no one. No matter how good you are, you have to prove yourself again."

5. Hristo Stoichkov (Barcelona)
Stoichkov once made a bold statement, saying, "I have no respect for Van Gaal. He is garbage." This outburst clearly highlighted the intense animosity between the Bulgarian forward and the Dutch coach. Stoichkov even went as far as advising Pedro against joining Manchester United, warning that Van Gaal would ruin his career.

6. Lucio (Bayern Munich)
The 2010 Champions League final between Bayern Munich and Inter Milan was an emotional match for Lucio, as he faced his former team, Bayern. After defeating his old club, Lucio revealed, "Van Gaal hurt me more than anyone else." This tension stemmed from the fact that when Van Gaal took over Bayern in 2009, he immediately sold Lucio to Inter Milan.

7. Giovanni (Barcelona)
"Van Gaal is like a Hitler to the Brazilian players. He’s always arrogant, acting superior, and has issues," recalled forward Giovanni in 2010. During his time playing under Van Gaal at Barcelona between 1997 and 1999, Giovanni went from being a regular starter to being relegated to the bench.

8. Victor Valdes (Barcelona and Manchester United)
Victor Valdes and Van Gaal clashed during their time together at Barcelona, and the tension continued when they reunited at Manchester United. At Barcelona, Van Gaal promoted Valdes from the B team to the first team, only to unexpectedly send him back to the B team later on, despite no issues with his form. Angered by this decision, Valdes refused to train, leading Van Gaal to threaten to sell him.

9. Rivaldo (Barcelona)
Rivaldo was one of the standout players under Van Gaal’s reign at Barcelona, winning back-to-back La Liga titles. However, in his third season, the forward requested a change of position from left wing to attacking midfielder, but things quickly soured. Rivaldo found himself benched for an extended period, and Barcelona ended up losing the league title. Van Gaal was dismissed at the end of the season.

10. Mark Van Bommel (Bayern Munich)
Van Bommel played for Bayern Munich from 2006 and worked under Van Gaal from 2009 to 2011. He was a key figure for Bayern before Van Gaal’s arrival, but after a smooth first season together, their relationship began to deteriorate. Van Gaal brought Luiz Gustavo into the lineup and announced that Van Bommel would no longer be captain. Feeling disrespected, the Dutch midfielder chose to leave for AC Milan.

