At half-time United must have wondered how they were behind.

They carried a genuine goal threat as Mason Mount took up intelligent positions in the number 10 role, Amad Diallo and Marcus Rashford attacked from wide areas and 20-year-old Collyer burst into the box when his workload allowed.

The problem was that Erik ten Hag’s side were found wanting at crucial times in both penalty areas.

Casemiro and Collyer were culpable for the Liverpool goals, while United’s attacking players took it in turns to waste clear chances. Diallo flicked a close-range header wide from Mount’s cross and the Ivorian also blazed over when presented with a chance to shoot by Aaron Wan-Bissaka, whose time at Old Trafford appears to be coming to an end as West Ham try to tie up a deal.

Kelleher twice denied Mount before tipping a mishit Rashford effort over.

The wasted opportunities continued to pile up after the break, although the momentum started to ebb from their game as the substitutions came.

Ten Hag may have a new contract, but United will need to do more than this to convince anyone that last season’s eighth-place finish was the aberration it was claimed to be.

And they have Manchester City in the Community Shield on Saturday.

“There were mixed feelings,” Ten Hag said. “I have seen positive bits, but the way we concede goals, we are, of course, not happy with it.”