Michael Carrick's side endured a quiet close to the window despite a squad that still looks light in key areas, with left-back proving a particular concern. Luke Shaw impressed and stayed largely fit last season, but with Manchester United competing on four fronts this year, the 31-year-old's only recognised deputy is 19-year-old academy product Harry Amass.
United held talks with Manchester City on Tuesday afternoon after Ait-Nouri's representatives offered the player to Old Trafford, initially enquiring about a loan.
City, however, would only sanction a departure on loan with an obligation to buy attached, terms United sources say held no appeal, and the move was abandoned as a result. The 25-year-old Algeria international joined City from Wolves in 2025 but has struggled to establish himself, dropping behind Nico O'Reilly in Pep Guardiola's pecking order and starting City's first two Premier League matches of the season on the bench.
It was not United's only late enquiry to go nowhere. The club also explored a deal for Leicester City youngster Louis Page before taking their business elsewhere after failing to agree a fee with the Foxes. Between the collapsed City move and the Page enquiry, United's deadline day amounted to a series of dead ends rather than fresh additions.
The lack of defensive reinforcement leaves Carrick with a threadbare set of options at left-back specifically, a gap that will need addressing when the window reopens in January if Shaw suffers any significant fitness setback between now and then. For now, United enter the season relying on the same personnel that carried them through a mixed campaign a year ago.
City's insistence on a loan-with-obligation structure reflects their own valuation of Ait-Nouri, who arrived from Wolves for a significant fee only last year and remains under contract for several seasons.
Allowing a direct Premier League rival to take him on a simple loan, with no guarantee of a permanent sale, was evidently not something Guardiola's club were prepared to countenance, even with the player himself understood to be increasingly frustrated by his lack of game time this season.