Manchester United topped their Champions League group drawing 1-1 against the Swiss club Young Boys on Wednesday but it was the Premier League giants’ young boys who were the talk of town.

The lead act was provided by Mason Greenwood, who plays with a maturity and intelligence beyond his 20 years, and that is why it is an enduring mystery why he is not at present involved with England.

With little at stake, United’s interim manager Ralf Rangnick made 11 changes from the team which beat Crystal Palace on Sunday. Greenwood gave United the ideal start, producing a super volley from a Luke Shaw cross to put the home side ahead in the ninth minute.

Rangnick called Greenwood a “massive talent”, praising him also for the work he did to set up Juan Mata for a chance for a second goal which the Spaniard was unable to make the most of the opportunity.

United were sloppy, though, and conceded several openings for David Wagner’s Swiss side who drew level three minutes before the interval. United’s Dutch midfielder Donny van de Beek poorly gave away the ball on the edge of his own box and Fabian Rieder curled it into the corner.

It was a reminder to Rangnick of the enduring flaws in this side. Just as he was celebrating United’s first home clean sheet of the season, against Crystal Palace on Sunday, he was shown the work still required to keep control.

United struggled to find any fluency after the break and Young Boys wasted several chances to win the game. But with United already assured of top spot in the group and a place in the last 16, Rangnick decided to give a chance to their academy products. United’s own young boys.

The rain teemed down at Old Trafford, but nothing could dampen the spirits of Rangnick’s final two substitutes, the 18-year-old Zidane Iqbal, a Manchester-born midfielder of Pakistani-Iraqi heritage, and Charlie Savage, also 18.

It was an emotional moment for Savage’s father, Robbie, a former Wales mid-fielder who was on BT Sport co-commentary duty. Savage Sr also came up through the United youth ranks, but never managed to get a game for the first team.

Zidane Iqbal became the first British South Asian footballer in Manchester United’s history when he replaced England international Jesse Lingard. Iqbal, born in Manchester to a Pakistani father and Iraqi mother, had trained with the first team on Tuesday.

Speaking to MUTV after the game, Iqbal, who wore shirt number 73, said: “It feels amazing, I’ve been working my whole life for this opportunity, it’s a dream come true, it’s just the start and hopefully I can keep pushing on.”

He is eligible to represent England, Iraq and Pakistan at international but has never been called up to an England age-group squad.