Louis van Gaal was booed by his club's own fans after Manchester United ended their Premier League campaign by beating Bournemouth 3-1 in Tuesday's re-arranged Old Trafford fixture.
In a game carried over from Sunday following a postponement caused by the discovery of a fake bomb accidentally left behind during a terror training exercise, United needed a 19-goal victory in order to steal past Manchester City into the fourth and final Champions League qualifying berth.
Goals from Wayne Rooney, 18-year-old Marcus Rashford, named in England's provisional Euro 2016 squad a day earlier, and substitute Ashley Young secured the three points, but it was only enough to lift Van Gaal's side above Southampton into fifth place.
Introduced to the crowd for a post-match address, the Dutchman was booed by pockets of the home support, before declaring, somewhat ironically: "I want to thank you for your unconditional support."
As Bournemouth's fans goaded him with chants of "You're getting sacked in the morning!", Van Gaal added: "You never let us down. Thank you for that. We will bring the FA cup home to you. You deserve it. Thank you."
The result secured a Europa League group place for United, while Saturday's FA Cup final against Crystal Palace may yet yield a piece of silverware.
But it was a tame end to the season, at a two-thirds full stadium, which laid bare United's stagnation under Van Gaal. The lap of appreciation that followed his address was cursory.
His Bournemouth counterpart, Eddie Howe, has enjoyed a much more encouraging season.
The south-coast club, who replied courtesy of a stoppage-time Chris Smalling own goal, finished their first ever top-flight campaign in 16th place.
But Howe said that Sunday's events had proved problematic.
"It was quite difficult, mentally," he said. "We did our best, but Man United were too good for us."