Manchester United boss Louis van Gaal has vowed to resign the moment he realises that he and his players no longer share the same "chemistry".

The Red Devils sit third in the Premier League table, one point behind leaders Manchester City, but criticism has been levelled at the Dutchman as goal-shy United struggle to entertain.

Quitting would not entitle him to compensation from the club, but the 64-year-old insists that he would not hang around waiting for the axe if his troops turned against him.

"The most important thing in my opinion is the chemistry between players and staff," he told a press conference. "That chemistry is the most important thing 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. I don't think there is another coach who decides to quit himself because of the money aspect, but I am like that.

"It's fantastic that people are saying when I'm gone, 'Oh, he was very good, he gave structure and was the basis for other things'. But the most important thing for me as a trainer, coach and manager is the chemistry between me and my players and my board. It should be good and otherwise I would be gone."

The Red Devils host West Ham United at Old Trafford on Saturday.