Ole Gunnar Solskjaer insisted that only titles matter at Old Trafford after United lost on penalties in the Europa League final to Villarreal.
"It's not a successful season of course," Solskjaer told a news conference after keeper David de Gea had his spot kick saved by his Villarreal counterpart Geronimo Rulli, who had just scored what proved to be the winning penalty.
"Sometimes one kick defines a season as a good one and sometimes a kick defines it's not. Nobody expected us to finish second in the league but the boys came up just short tonight unfortunately.
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Trophies matter and that's what matters at this club so no it's not a successful season. It's the short answer.
On the night, United fell behind after Gerard Moreno stretched to reach Dani Parejo's free kick and steered the ball past De Gea to open the scoring in the 29th minute.
They levelled 10 minutes into the second half when Edinson Cavani poked the ball home after collecting Marcus Rashford's deflected shot, but they did not have the creativity - or the bench - to add another and were left ruing their two runners-up spots this season.
"Second doesn't count for nothing. Manchester City win the league, we finished second. Doesn't mean nothing. Villarreal won the Europa League, we finished second. For us it's nothing," said Rashford.
"I don't want to hear 'they were so close' because it means nothing. One winner, one loser. Today we lost. We have to find out why and make sure next time we don't lose."
Solskjaer, who said he had considered replacing De Gea with another keeper for the shootout given the Spaniard's terrible record - 36 without a save after Wednesday's game - said he was hoping the club would recruit "two or three" players to strengthen his starting eleven for next season.
"We will come back next season with more desire and hunger. We have to give 110%," said Rashford.
"To win big trophies you have to show sacrifice. I know in every club they don't have this sacrifice. In the top clubs they do. That's why they win trophies.
We're close, I promise we're close.
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