United looked into the prospect of a move for the former academy graduate, but they failed to move quickly and decisively enough to secure his return.
Insiders believe Welbeck, 35, might well have made the move - but instead he switched from Brighton to Chelsea, who wanted to add Premier League experience and a reliable goalscoring option to their squad.
It did not seem a particularly significant moment for United at the time but as they prepare to take on Atletico Madrid in the Champions League, they lack central striking options and the moment may now be seen as a missed opportunity.
Benjamin Sesko has suffered another injury setback, while Matheus Cunha and Bryan Mbeumo have been used in central roles that do not necessarily suit their strongest qualities.
United are also having to consider how best to bring Joshua Zirkzee into the picture, with the Dutchman still fighting to establish himself as a regular first-team option.
The uncertainty leaves Michael Carrick under pressure and without an obvious No.9 profile to build his attack around.
Welbeck could have offered the kind of short-term alternative United now lack - and they may even have to return to the transfer market in January to find a new option.
The upcoming October 31 meeting with Chelsea may yet take on added significance, too, if United are still struggling and Welbeck plays a role for the Blues.
By then, United will hope to have greater clarity over Sesko's fitness and a more settled attacking structure.
With no natural centre-forward having established himself as the answer, United's decision not to pursue an attainable target last summer looks increasingly questionable.
Dean Jones has been a transfer news and football insider for Flashscore since 2025, as well as a journalist for leading UK newspapers and websites over the past 20 years, establishing himself as an authoritative and trusted voice in the industry.
