In selecting a Manchester United XI that may never again play together due to its blend of fringe and senior squad members requiring game-time, Ralf Rangnick will have pleased all fielded while gleaning precious information regarding his new squad.

Heading the file is how Mason Greenwood sparkled with a spectacular opener and was at ease executing the high press Rangnick demands. There were debuts, too, for the 35-year-old Tom Heaton and youngsters Zidane Iqbal and Charlie Savage, each 18. The German, though, was less enamoured of the way Donny van de Beek dozed to allow Young Boys an equaliser and the general sloppiness he observed.

Rangnick, who changed all 11 players, said: “What was really annoying was the way we gave a goal away because we played too many balls into the first line of their pressing area.”

United had already qualified as Group F winners and although victory was, of course, sought, this was a second satisfying match in charge for Rangnick before Saturday’s trip to Norwich. In Monday’s draw for the last 16 United can be paired with only six teams: Atlético Madrid, RB Salzburg, Sporting Lisbon, Internazionale, Benfica and Paris Saint-Germain.

Amad Diallo, positioned on the right in Rangnick’s attacking trident, scuffed an early chance when clear in on Guillaume Faivre’s goal. The Ivorian, 19, was soon shown how by the lethal Greenwood. This was fluid from United as Anthony Elanga fed Luke Shaw who wheeled along the left, flipped the ball into the area, and the centre-forward spun 180 degrees in the air to smack home a scissor-kick that, sweetly, eliminated Faivre as a factor.

“Technically, I have no worries,” said Rangnick of Greenwood. “Today he also showed, not only because of that beautiful goal, that he’s a massive talent: left foot, right foot, good on the ball, also the way that he set up the goal for Fred on Sunday [versus Palace]. Still, it’s about continuity, he has to develop physically but technically, for his age, he is a great player. My job is to develop him, to make an athlete out of him, and if he manages to do that can be a regular player for this club.”

Rangnick, dismayed at any possession being lost via errant passing, was hardly content when Eric Bailly did so and thus the German offered the centre-back a stern stare. The 63-year-old was happier with an arcing Juan Mata diagonal that cleared Young Boys defence and which Jesse Lingard’s deft touch pulled from the air though when Shaw took over the referee, Benoit Bastien, inadvertently blocked the left-back, much to the home crowd’s chagrin.

Greenwood’s class was next evident when he muscled in from the left all the way into the area and laid off to Mata who, again, lacked the killer touch.

Yet the measure of how easy this all was for United was illustrated in Fabian Lustenberger, the visiting captain, smashing a regulation 15-yard pass out. Rangnick’s men were cruising until nonchalance cost them: Van de Beek was too casual when passing to Wan-Bissaka – who ended as an injury doubt for Norwich due to two knocks – and Fabian Rieder swooped and from 20-plus yards beat Dean Henderson.

If Rangnick threw a metaphorical tea cup or two at half-time, his team responded. Elanga burned down the right, pulled the trigger and went close to pushing United ahead again but Faivre saved. Then, bright work from Diallo split Young Boys, and Lingard received but could not profit.

This was the tale of United’s evening: Greenwood apart, no one in home livery was clinical. Diallo and Elanga provided serious speed at the top of the team but there was a phase when United meandered, while Young Boys seized the ball and initiative.

Better was a moment taken straight from the Rangnick playbook of pressing. Greenwood sprinted back from halfway, dispossessed, spun and passed to Lingard who, on advancing, fed Elanga. The forward danced forward and fired at Faivre whose low-to-the-turf stop impressed.

David Wagner, in a bid to claim a Europa League berth, made a triple substitution and this came close to an instant dividend. Vincent Sierro, one of the new men, pinged a corner direct on to Lustenberger’s boot but he blasted over.

Could United unpick Young Boys again for the winner? They could not, but in a nice touch Rangnick now gave the 18-year-olds Iqbal and Savage their bows in closing moments they will not forget soon, Heaton having entered previously in the period.