Ole Gunnar Solskjaer's side will not play in Europe's elite club competition next season after a 1-1 draw away at already relegated Huddersfield.
Ashley Young described Manchester United's failure to qualify for the Champions League as a "massive blow", but insisted their effort at Huddersfield Town could not be questioned.
Sixth-placed United drew 1-1 at Huddersfield on Sunday and cannot now finish in the Premier League's top four, with Isaac Mbenza's breakaway goal doing the damage and cancelling out Scott McTominay's early opener.
The result caps a miserable season for United, who have slumped again after an initial upturn in form following Ole Gunnar Solskjaer's arrival in place of José Mourinho.
Captain Young acknowledged that missing out on Champions League football next season is hard for United to take, even if they would rather have loftier ambitions.
Young: "A massive blow for Manchester United"
"It's a massive blow for a club like Manchester United," he told Sky Sports.
"I've said all along that when you're talking about a club like Man United fighting for top four, that's not what we want to be talking about. We should be talking about higher up, winning trophies, winning titles, and I think that's the disappointment.
"Ole and the staff will be prepared over the summer, ready to go for next season."
However, despite mounting criticism regarding the United players, Young insists their attitude was right against Huddersfield.
"I can't fault the effort and the attitude. We applied ourselves - especially in the first 20 minutes when it was all us," he said. "It's tough to take their goal.
"We knew we needed other people to help us, but we need to help ourselves and we haven't done that today. It's a disappointment."