Speculation had built around who would inherit the shirt after Rasmus Højlund's departure left it vacant, with many assuming Benjamin Šeško was the natural fit given his status as Manchester United's marquee summer signing at centre-forward.
But the Slovenia international had no intention of changing, with the number carrying personal significance from his time at Red Bull Salzburg and RB Leipzig before his move to Old Trafford.
Rashford's own numbering history reflects a career that has taken in several clubs and countries in a short space of time.
He wore the nine during his loan spell at Aston Villa last year, but was given the 14 at Barcelona and wore 11 for England at the World Cup. Before his run of loans, Rashford had long been associated with United's number 10 — a shirt now worn by Matheus Cunha, leaving nine as the closest available number carrying similar weight for a player once seen as the long-term successor to the club's most storied numbers.
The numbering situation is a minor footnote in what has been a significant summer of change up front at Old Trafford, with Šeško arriving as United's central striker of choice and Rashford returning to the club he came through as an academy graduate after spells away on loan.
Højlund's exit, meanwhile, closed the book on a spell that never fully delivered on the promise shown when he first arrived from Atalanta.