Michael Carrick's first Man United team was leaked over an hour before it was due to be released on Saturday morning.
Dressing room leaks have been a recent problem at Old Trafford, with former boss Ruben Amorim said to have launched an investigation within the United camp after his full starting XI surfaced before they were due to face City in December 2024.
'I know that story,' Amorim said at the time. 'I don't know, I think it's impossible to fix nowadays because you have a lot of people in the club, the players talk with agents.
'I don't know, you can talk with friends, so it's hard to know. It's not a good thing but let's move on and go to the next one and see if they find the next starting XI.'
But the mole appears to have come again after Samuel Luckhurst, United correspondent at The Sun newspaper, shared the lineup before Saturday's Manchester Derby.
'It is unclear if that leaked XI is accurate or deliberately incorrect. In the past, some inaccurate United XIs have leaked in an attempt to unearth the source,' Luckhurst wrote alongside Carrick's teamsheet.
The starting XI, which included the return of Kobbie Mainoo and Bryan Mbeumo proved to be correct.
After the leak under Amorim, speculation began swirling that former United winger Alejandro Garnacho's brother was responsible - ramped up by him being dropped for that tie against City.
But club sources told the Manchester Evening News at the time that it was 'rubbish' to suggest Garnacho's omission was related to those suggestions.
The report also quashed any rumours that Amad, United's Ivorian winger, was a source of the leaks.
Despite the apparent setback within the dressing room on Saturday, Carrick will be hoping he can get his interim United tenure off to the best possible start against their local rivals.
He starts Senne Lammens in goal, with a back four of Diogo Dalot, the returning Harry Maguire, Lisandro Martinez and Luke Shaw.
Ahead of the defence sits Casemiro and Mainoo, with captain Bruno Fernandes, Patrick Dorgu and Amad making up the three behind Mbeumo.
The 44-year-old's first squad did bring surprise omissions such as Benjamin Sesko and Matheus Cunha, who start on the bench, but Carrick explained his reason for dropping them.
'We have a good squad. There will always be players disappointed not to start, but finishing the game can be even more important. They have huge talent and it's nothing personal,' he told Sky Sports.