Van Gaal has come under fire this season for his conservative tactics and United's subsequent failure to play the kind of entertaining football that was their hallmark during the Alex Ferguson era.
United fans have occasionally shown their displeasure by booing the team's dour performances and even more worrying for van Gaal, it has been reported that several players are unhappy with his dull style.
Although United, who face West Ham on Saturday, are third in the Premier League, they are in danger of elimination from the Champions League ahead of their final group game at Wolfsburg next week.
That would be a big blow to the Dutchman's credibility and, while van Gaal insists he has a good relationship with his players at present, he made it clear he would have no qualms about quitting if the situation soured.
“The most important thing is the chemistry between players and staff,” Van Gaal told reporters on Friday.
“And when I have the feeling that the chemistry is there, I will always work to my utmost best.
“But when I have a single feeling that it is not like that, I'm the first coach that quits and I have proved that already with my former clubs and former jobs.
“Yes, of course because I always gave my clubs structure and I think structure is very important in a club, but also in a company, everywhere.”
When asked about his relationship with his players, Van Gaal said: “It's good.”
Yet, as Van Gaal pointed out, he has walked away from clubs of his own accord during his 24-year management career.
After falling out with a number of players, Van Gaal left Barcelona during his second spell at the club and he quit his role as Ajax technical director following a power struggle with then manager Ronald Koeman.
Van Gaal also threatened to walk away from AZ Alkmaar in 2008 after finishing 11th in the Eredivisie, but was persuaded to stay on and led the club to the title the following year. – AFP
Original source: Van Gaal threatens to quit United