The approach, reported by 225foot, comes at a moment when Diallo's standing at Old Trafford has shifted: Bryan Mbeumo's arrival and strong early form on the right flank have squeezed his minutes under manager Michael Carrick, opening the door to interest elsewhere in the division. Villa see the 24-year-old as exactly the kind of attacking reinforcement they have been targeting.
Persuading Manchester United to sell will not be straightforward. Diallo is tied to Old Trafford until June 2030, is valued by Transfermarkt at roughly €45m, and is set to feature in the Champions League this season with a club he still hopes can deliver a Premier League title.
United handed him that long-term deal only last year specifically to discourage suitors, so there is no obvious financial pressure on them to negotiate. Whether Aston Villa's project is compelling enough to change his mind is, ultimately, a question only Diallo can answer.
He arrived at United from Atalanta in January 2021 for a fee that could rise to £37m, and has gone on to make 97 appearances, scoring 16 goals and adding 16 assists. A move would reunite him with Aaron Wan-Bissaka, who left United for Villa Park earlier this summer, and would rank as Emery's ninth signing of a busy window.
Diallo's versatility - comfortable on either flank or in a more central attacking role - is a large part of the appeal for Villa, who lost Ollie Watkins to Al-Hilal earlier in the window and have been steadily rebuilding their forward options ever since.
The fact that a firm, official bid has been lodged - rather than mere interest - suggests Villa believe there is at least a chance of forcing the issue before Tuesday night.