Louis van Gaal was booed by a number of Manchester United fans as the under-fire manager thanked them for their "unconditional support".
A topsy-turvy campaign ended with a 3-1 win at home to Bournemouth on Tuesday, with Wayne Rooney, Marcus Rashford and Ashley Young scoring before Chris Smalling turned in a late Max Gradel effort.
That was too little, too late for many fans, with Van Gaal booed by a significant section of the crowd when addressing the fans after the game.
"I want to thank you for the unconditional support of you," he said.
"Whenever we have played, however the things have gone on the field, you never let us down.
"Thank you for that and we want to bring the FA Cup home. You deserve it. Thank you."
Many applauded at the end of Van Gaal's address, but Bournemouth fans goaded him with chants of "you're getting sacked in the morning".
Fresh speculation linking Chelsea manager Jose Mourinho to the Old Trafford helm emerged before the match.
Asked by Sky Sports if he understood the booing fans, Van Gaal said: "Of course, but the expectation is very high. The fans expect a lot, these expectations are too high. We are a team in transition."