With more than an hour gone at Old Trafford and no end in sight to Rasmus Hojlund’s marathon goal drought, Ruben Amorim looked to his bench and summoned Chido Obi.

Off went Hojlund who has now gone 18 hours and 38 minutes without a goal since his double against Viktoria Plzen in the Europa League way back in mid-December.

The only time he threatened Fulham’s goal in this FA Cup tie came in the 14th minute when Christian Eriksen crossed from the left and Hojlund got free of Calvin Bassey to meet the ball first time at the near post but skied it high into the Stretford End.

So on came Obi with just two appearances and 21 minutes under his belt. The younger of the two Danes by some distance, having only turned 17 in November. At 6ft 2in, he carries a presence but the spindly legs belong to a young man whose body still has plenty of developing to do.

Considering the £600million spent under Amorim’s predecessor Erik ten Hag, it seems obscene that the player next in line behind Hojlund is a teenage rookie. Let’s not forget that of the 10 players unavailable to Amorim on Saturday, none of them are strikers.

Man United exited the FA Cup on Sunday night after losing a penalty shootout against Fulham

United’s £72million Danish striker Rasmus Hojlund failed to score for the 18th game in a row

Of that transfer spend, £72m of it went on Hojlund which seems to look more inflated with each passing game. He has played in 18 of them now without a goal.

How have the people now running United’s recruitment allowed this situation to develop? Money is tight at Old Trafford these days, but with £30m available in the January window and a desperate need for goals all too apparent, United spent it on a new left wing-back in Patrick Dorgu.

This has become a Frankenstein’s monster of a squad, pieced together bit by bit by different managers and regimes.

But the failure to sign a top striker is inexcusable. Ten Hag wanted Harry Kane and had to be satisfied with Hojlund. Last summer, Ivan Toney was available but United spent £36.5m on Joshua Zirkzee instead. Zirkzee is improving but he is not a centre-forward in the conventional sense.

Once again on Sunday they had to rely on their captain and top scorer Bruno Fernandes, a midfielder, who scored his 11th of the season. All of them have been scored since Ten Hag left. Still it wasn’t enough to keep United’s hold on the FA Cup.

Watching it all unravel again, the club’s record goal scorer Wayne Rooney had his own take on the situation.

‘If I’m a top player playing in a different country and Manchester United came to sign me now, I’d be thinking “I’m not sure”,’ said Rooney.

The Red Devils improved after Hojlund was replaced by 17-year-old Chido Obi on 68 minutes

United scored three of their five penalty kicks on Sunday but Joshua Zirkzee did not hit the net

‘United have spent a lot of money over the last 10 years. The structure hasn’t been there because a certain manager hasn’t had a long enough period of time.

‘They’re buying players like (Romelu) Lukaku and (Paul) Pogba, all these players are coming in as individuals and it looks like there hasn’t been a long-term plan to have this way of playing, this style and identity of how we want to play.

‘Every time they’re starting to move forward a bit, it gets ripped up again because they’ve got a different style.’

To be fair to Obi, he has been scoring goals for fun in United’s youth teams since joining the club from Arsenal, and posed more of a threat than Hojlund in the 52 minutes he was on the pitch including extra-time.

The goal opened up in front of him when he pushed Bassey off the ball, but his shot was so wide that it was heading for the corner flag. Then a follow-up effort a few minutes later went narrowly wide.

But his big opportunity arrived at the end of the first period of extra-time when Fernandes and Zirkzee combined to send Obi into the box. This time, he showed more composure and confidence despite the presence of two Fulham defenders to draw Bernd Leno and clip the ball over him, but the Fulham keeper instinctively thrust his left arm into the air to deny him.

‘What I like about him is that he’s put himself in some really good positions,’ added Rooney. ‘He was a little bit naive with some of his chances, but I think it’s really encouraging for Manchester United.

Zirkzee was consoled by United manager Ruben Amorim following Sunday’s FA Cup defeat

A dejected Amorim pictured applauding United’s supporters alongside Hojlund at Old Trafford

‘They’ve obviously got Zirkzee and Hojlund not scoring. Now, that might be another option moving forward in the season. I’ve been really impressed with him.’

It was perhaps for the best that Leno’s saves from Victor Lindelof and Zirkzee in the penalty shootout meant that Obi and teenage debutant Ayden Heaven weren’t exposed to the pressure of stepping up to the spot in front of the Stretford End. The buck would have stopped with them at some stage.

Instead, Obi emerged from his home debut with considerable credit after being fast-tracked into the first-team in recent weeks.

Might Amorim finally be starting to lose patience with Hojlund and consider starting the youngster sooner rather than later?

‘We have a problem with goals,’ said the United head coach with no little understatement. ‘I will focus on the next game and choose the best players to win the match. Anything can happen.’