United's 2-1 defeat at Danish minnows FC Midtjylland was the latest disappointment for Van Gaal, whose side sit fifth in the Premier League, six points off the top four.
Van Gaal has been criticized for his side's turgid style of play and he is now 8-11 with several bookmakers to be the next to go.
Former Chelsea manager Jose Mourinho has reportedly been making noises that he would like the job.
But Van Gaal remained defiant on Thursday, blaming the defeat on bad luck, with an injury in the warm-up to goalkeeper David De Gea the latest blow.
“I think it is the law of Murphy,” he said, referring to Murphy's Law, which states that “whatever can go wrong, will go wrong”.
“When you have a list of 13 injured players and a few minutes before the game we can add another player to the list, then it is difficult to cope with such a list of injured players.”
“It is nothing to do with attitude. All of the players want to perform in an excellent way so attitude is not the case. We were not winning the second balls. That is my analysis.” – DPA
Original source: LVG favourite to be sacked