Zlatan Ibrahimovic was the last holder of the coveted shirt, but he vacated it in March this year when signing for LA Galaxy.
Previously, Wayne Rooney had adorned the shirt for 10 years from 2007 to 2017, before switching to Everton.
It has long been reserved for the club’s star marksman and past wearers include Ruud van Nistelrooy, Teddy Sherringham, Mark Hughes and even David Beckham for the 1996/97 season.
But 20-year-old Marcus Rashford is the latest recipient of the shirt, debuting it during a pre-season friendly against Bayern Munich.
United confirmed via Twitter that Rashford would indeed don the number for the upcoming season.
The match marked a sour end to a vociferous pre-season tour for United, as they lost 1-0 at the Allianz Arena.
Jose Mourinho has complained about his threadbare squad over the last few weeks, with many players enjoying extended holidays after lengthy World Cup campaigns.
“My CEO knows what I want and I still have a few days to wait and see what happens,” he told MUTV before the loss to Bayern.
“The other clubs who compete with us are really strong and already have fantastic teams. Or they are investing massively like Liverpool, who are buying everything and everybody.
“If we don’t make our team better it will be a difficult season for us.”
United boss Mourinho also had an embarrassing moment during the game where, after using three substitutes, he sought approval from Bayern boss Niko Kovac to make an extra sub.
Eric Bailly and Victor Lindelof were given a chance to impress the Portuguese in Munich, but Toby Alderweireld and Harry Maguire remain transfer targets at centre-back.