A serial winner of trophies, Louis van Gaal has also never been afraid to let a player know who is in charge, regardless of how high profile the footballer in question may be.
The latest two players to have fallen foul of the Van Gaal approach are Robin van Persie and Victor Valdes. The former of that duo has already departed Manchester United, while Valdes's days at Old Trafford appear to be numbered.
But, why does the 63-year-old have such a fearsome reputation? Here, Sports Mole has taken a closer look at five of the Dutch manager's biggest bust-ups.
1. Rivaldo
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In 1999, the Brazilian playmaker was at the peak of his powers. On the back of having helped Barcelona to win a second La Liga title in a row from wide on the left, he was named the FIFA World Player of the Year.
Full of self-belief, Rivaldo demanded that Van Gaal play him in a more central position, which resulted in the Brazilian being dropped. He soon regained his spot in the team, but Barca surrendered their crown to Deportivo La Coruna and Van Gaal was sacked, much to the delight of Rivaldo and the media, many of whom had sided with the playmaker.
Rivaldo told reporters: "I don't like Van Gaal and he doesn't like me."
2. Giovanni
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The arrival of Van Gaal at the Camp Nou all but ended Giovanni's status as a key player at the club. The head coach was often critical of what he perceived to be a lack of effort from the Brazilian in training, while the player himself struggled to cope with his manager's harsh style.
Giovanni said to Marca: "Van Gaal is the Hitler of the Brazilian players. He is arrogant, proud and has a problem. My life with him was horrible, the Brazilians did not want him, he put me down and also fought with Rivaldo and Sonny Anderson. He always gave us the excuse that we were not training well."
3. Hristo Stoichkov
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During his two spells as a Barcelona player, the Bulgarian scored 118 goals in 254 appearances. But, his second stint was cut short by Van Gaal, who opted to use the striker just four times during his one season as his manager.
Stoichkov said to L'Equipe: "I have no respect for him, he's scum. One day, when I was injured, I was with my wife at Camp Nou and Van Gaal went up to her.
"He asked her how it was possible that she married someone like me. She responded that I was a Ballon d'Or winner. "My departure in 1998 was the fault of Van Gaal, for sure."
4. Luca Toni
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The Italy international was a big favourite among supporters when Van Gaal took charge of Bayern Munich in 2009. However, the pair soon fell out when Van Gaal forced the striker to sit up straight during a team meeting.
An Achilles injury ruled the frontman out for a while and when he returned to fitness, he found that his place had been claimed by Miroslav Klose. There was no way back for Toni, who was loaned out to Roma soon after and never returned to the club.
Toni told reporters: "The way Van Gaal treated the key players was unworthy on a human basis."
5. Mark van Bommel
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While Toni was doomed from the start, it seemed that Van Bommel's position in the Bayern team was safe upon Van Gaal's arrival. After all, not only were the pair both Dutch, Van Bommel was still regarded to be one of the best holding midfielders in European football.
Nevertheless, Van Gaal had soon added Luis Gustavo to his Bayern squad and as it turned out, the Brazilian was there to replace Van Bommel, who was first dropped, then sold to AC Milan.
Van Bommel told reporters: "I had a little problem with him in 2010 in December. Maybe I could have settled down and let it go, but that is the way I am. That is my character and it was his character as well."
Liam Apicella
