Manchester United on Saturday faltered once more, losing 1 – 0 to Southampton at Old Trafford.
Substitute Charlie Austin’s header went past De Gea at the 89th minute to give the Saints the three points.
United are fifth in the Premier League, five points behind fourth-placed Tottenham and 10 off leaders Leicester.
Speaking after the match, United coach Louis van Gaal said the fans were right to boo him.
“They are right to boo. I cannot deny that, I saw the match,” said Van Gaal.
“For better or for worse we have to stick together,” added the Dutchman after his side’s six league defeat of the season.
United have taken 37 points from their first 23 games, their lowest total in the Premier League era and three points fewer than under David Moyes during the 2013/14 season.
“We are working very hard, but we have had a lot of injuries. That you cannot change.”