David de Gea leapt to his right and tipped Kevin De Bruyne's shot around the post. "Vamos!" he bellowed to team-mates gathered for the Manchester City corner, banging those overworked gloves together.

Cristiano Ronaldo, who had just congratulated the Manchester United goalkeeper on his latest brilliant save, gazed around the penalty area, shaking his head.

The reactions looked different but echoed the same feeling, presumably the one felt by the 70-odd thousand United fans inside Old Trafford. It's the same thing they felt when losing 4-0 at half-time to Liverpool. It's largely the same thing they felt seven years ago, when consecutive home defeats to Liverpool and City sounded the death knell for the David Moyes era.

How much longer can this go on?

It was the 5-0 scoreline that was most damaging about the game last month against Jurgen Klopp's side, and the reason Ole Gunnar Solskjaer came as close as he did to losing his job. The Manchester derby was, in essence, no different; it was a thrashing in all but the scoreboard.

And it will prompt the same question.

The 3-0 win over a miserable Tottenham secured Solskjaer's position for at least another week and saw Antonio Conte, his most obvious and available replacement, head to north London. Yet, as the United manager likes to say, "one swallow doesn't make a summer". He knew there had to be sustained improvement, that wins over Atalanta in the Champions League and Manchester City were vital to show he could arrest a decline that has seen his United become the first to concede in 13 consecutive home matches for the first time since the 1950s.

Instead, United repeated the 'Liverpool Week': a poor Champions League performance salvaged by Ronaldo, and utter embarrassment at the hands of their domestic rivals.

Solskjaer had won four of his first eight meetings with Pep Guardiola, giving him the best win rate of any manager to face the City boss at least five times. He'd also presided over a four-game unbeaten league run against their neighbours, whose recent success relative to United – nine major trophies since the Red Devils last won anything – has seen them go from noisy to ear-splitting. The last time these teams met in front of a full crowd, a muddied Scott McTominay slid across the soaked turf after lobbing Ederson in the final seconds, a striking visual metaphor for Solskjaer's team: imperfect, unpolished, but going somewhere.

In the second half of Sunday's game, after Eric Bailly's senseless own goal and a gift for Bernardo Silva, Solskjaer's tenure entered a perverse kind of scoreline purgatory: would he be safe if it finished 2-0, or 3-0, or 4-0? Was it not bad enough that City could come to Old Trafford and treat it as a training exercise, limiting their opponents to one shot on target?

This is what Solskjaer's United have become: a listing wreck, held together by default. Results are bad, but not quite bad enough; supporters are fed up, but they won't turn on a club legend; the owners fear the risk of change more than the cost of inaction.

"I give up," said former captain Roy Keane on Sky Sports. Solskjaer won't; not after nearly three years in charge. The pedestrian, goalless second half against City will probably count in his favour with the board, too.

But 'only' losing the derby 2-0 cannot ever be acceptable. It certainly isn't what Ronaldo signed up for, and as long as things persist as they are, he'll be shaking his head for many months to come.