Three Manchester United transfer failures that have allowed Kobbie Mainoo's success

Before Sunday evening, the last time Kobbie Mainoo was substituted, with his team losing, the Old Trafford denizens booed loudly.

In the debriefs of that disappointing draw with Burnley in April, Erik ten Hag protested Mainoo was "f****d" as he had started three games in seven days. Manchester United had scraped past Championship side Coventry and Championship-bound Sheffield United. Here they were, goalless against Burnley, now in the Championship.

Christian Eriksen was waning and his age showed when he squandered a two-on-one. When it was Mainoo's number that was up, the outcry was audible and widespread.

It also reflected how pivotal and popular Mainoo is at United. Now the love-in is growing nationwide. The 19-year-old was one of a handful of respectable performers in England's fortuitous progression past Slovakia and, of all the players to make way at 1-0 down in the 84th minute, Mainoo was an inexplicable choice.

READ MORE: Three key signings, two coaches and four more transfers could come in at United

READ MORE: Ten Hag has seven games to fuel United's progress

England's games have been soundtracked to boos but, remarkably, there seemed to be only appreciative applause for Mainoo's withdrawal when their fans would have been forgiven for airing more disapproval in the direction of Gareth Southgate.

Had England been packing their bags this morning, the upside is it would have kiboshed the possibility of a former cycling team principal championing the former Middlesbrough manager to manage United. United should not touch Southgate with a bargepole.

His indecisive handling of Mainoo is another red flag. Mainoo was dropped on the eve of the European Championship after a subdued performance in the friendly defeat to Iceland that a substitute goalkeeper was responsible for. Southgate played the populist by starting the cavalier Trent Alexander-Arnold in midfield against Serbia and Denmark. Then the workhorse Connor Gallagher lasted a half against Slovenia. In the round-of-16, he came full circle by putting Mainoo in the centre circle.

As bad as England were in Gelsenkirchen, they were better with Mainoo underpinning their proactive passages of play. John Stones has been tamed with the Three Lions on his chest, Declan Rice wanders too far forward and those positional problems had a knock-on effect on Jude Bellingham.

Yet England were saved by the Bell, as the back pages put it. Southgate was not questioned about the timing of Mainoo's withdrawal and his reluctance to make more substitutions during the 90 minutes became inconsequential, for now.

Southgate deserves little credit for Mainoo's impact. He initially overlooked him for the squad against Brazil and Belgium in March, only to belatedly add him and start Mainoo in the latter fixture. Mainoo was the man of the match in that 2-2 draw at Wembley.

What foresight to pick a United-bred specialist midfielder who consistently performs unflappably in a pressure-cooker environment. Mainoo showed teeth in bear pits at home and abroad, scored against Liverpool and slotted in the winner against Manchester City in an FA Cup final, another man of the match performance. He plays with an authority that could be mistaken for one of the midfield metronomes developed at La Masia.

In a parallel universe where the Glazer family put their hands into their pockets, Mainoo-Rice-Bellingham might have been a United midfield triumvirate. Rice was identified as a potential target as far back as Jose Mourinho's final months in charge, he was curious enough to ask Harry Maguire and Luke Shaw about the club in 2021 and United held exploratory talks with his father in 2022. United got a 16-year-old Bellingham into the building at Carrington in March 2020.

Bellingham dodged a bullet. Perhaps he would have galvanised United like Eric Cantona and ended their title drought. He has probably never paused to wonder, having got his hands on the European Cup, a competition United have reached the quarter-finals of twice in the past 13 years.

The England midfield international United misguidedly plumped for is not even in Germany. Mason Mount was usurped by Mainoo in November. If Mount is to make a success of his United career it is going to have to be elsewhere in the team.

United's misses have been offset by a hell of a hit in Mainoo. He has played as a 6 and an 8 and he has the skill set to reinvent himself as a playmaker. Mainoo's graduation from youth team to first team is a blueprint for United's other tyros to follow.

Mainoo appeared in the first official image of the new United kit in a recreation of Alejandro Garnacho's celebration against West Ham. The Mancunian's squad number is still listed as 37 but it would be presumptuous of any supporter to have that printed when an upgrade is merited.

Substituting Mainoo is unlikely to be as regular next season.