The disappointment for United supporters continued beyond the final whistle. During the second half, Hull's stadium announcer told fans that two trains returning to Manchester had been canceled, prompting loud cheers from the home crowd.
"You should have come in a taxi," Hull supporters sang as the visiting fans faced an inconvenient journey home.
For United, however, the bigger concern was what had happened on the pitch. Hull scored twice in the first half to secure their first ever top-flight victory over Manchester United and their first league win against them since 1974.
Former United striker Wayne Rooney felt the visitors had struggled to create enough chances.
"They didn't create much, which was the biggest worry," Rooney told BBC Sport. He suggested that facing a promoted side away from home in the opening match could be difficult, but felt United did not appear ready for the challenge.
Alan Shearer offered a different explanation, suggesting fitness may have played a role. However, that assessment was questioned given United's extensive preseason schedule and the fact that most of their squad had been training since early July.
There were nevertheless clear concerns about United's attacking threat, particularly before and after Marcus Rashford came on at halftime for his first appearance for the club since December 2024.
Captain Bruno Fernandes also pointed to problems with the team's pressing and defending from set pieces.
"We give too much of the ball to them," Fernandes told TNT. "We need to press a little bit more, be more aggressive."
Set pieces had reportedly been identified as an area Hull intended to exploit, and United were unable to prevent the promoted side from taking advantage.
Despite the disappointing result, United manager Michael Carrick maintained a calm public demeanor. He insisted the defeat should be viewed as one poor result rather than evidence that everything was wrong with his team.
"It's just one game," Carrick said. "We're disappointed we haven't won. We've got to soak it up and come back stronger."
Carrick admitted, however, that the loss was painful behind the scenes. He said his calm appearance should not be mistaken for a lack of emotion.
United's next Premier League match comes at Old Trafford against another promoted side, Ipswich, on Aug. 30.
Carrick has already rejected suggestions that United were handed an easy opening schedule. The defeat at Hull provided a stark reminder that promoted teams can pose a serious threat.
The club has agreed a £70 million deal for Brighton midfielder Carlos Baleba, but Carrick insists the result will not force him to change his approach.
"I understand the responsibility I've got," he said. "We've lost today and there's questions to be asked. But it doesn't mean everything's wrong."
