The Dutchman has come under severe pressure this term, with the Red Devils unlikely to improve on last season’s fourth-place finish.
United could even finish outside the Champions League places altogether – they are currently sixth with eight matches remaining – and Van Gaal has conceded for the first time he could pay the price with his job.
“I think the board has to evaluate after the results of this year, what they have to do,” he said.
“I cannot predict that when I do not know the facts. First you have to see the facts, I have always said that.
“The results and the titles and Champions League positions you can only say at the end.
“I am a rational person. I know a Manchester United manager has to win something, but I am still working on that.”
Van Gaal has been criticised for failing to get the best out of many of the players at his disposal, with former winger Angel Di Maria recently claiming that he struggled at United because he was played out of position.
But Van Gaal has hit back at the Argentina international, insisting he must take some of the blame for an underwhelming single season at Old Trafford in 2014/15.
“I have never seen a player who doesn’t look at himself [like him].
“He looks at the way he performed here and [claims] it is always the fault of the manager.
“So he is one of the players who has no self-criticism. Unfortunately it is my life as a manager. It is always like that.”
United host Everton on Sunday as they continue their challenge for the Champions League places, with fourth-placed Manchester City in action against Bournemouth on Saturday.