Paolo Di Canio was sacked after some senior Sunderland players complained to the club about him, Sky sources understand.
The Italian lost his job on Sunday night just five games into the Premier League season - and hours after he held a training-ground inquest into Saturday's 3-0 defeat at West Brom.
In the fallout from that meeting, some of the club's senior men went above Di Canio's head to express their concerns about his management style.
And the board of directors - already considering the manager's position after he strode onto the pitch at West Brom to face down the travelling supporters - then acted to terminate his contract.
In his six months on Wearside Di Canio increased the workload in training and was at times publicly critical of his players but - this season, at least - his methods have not paid off.
Sunderland have taken just one point from their five league games to date, and academy coach Kevin Ball will be in charge for their next two fixtures - Tuesday's Capital One Cup tie against Peterborough and Sunday's home game against Liverpool.
Roberto Di Matteo is the bookmakers' early favourite to replace Di Canio, but in the meantime Ball - a player on Wearside for almost all of the 1990s - will reprise a role he previously held for 10 games following Mick McCarthy's 2006 departure.
He said: "The situation last time was slightly different to this time, but it did give you an experience, whether it be for one or 10 games.
"I enjoyed it last time and I hope I feel the same way about this one as well. It allows you to say, 'Well, I have done it before, it's not something that's unexpected'.
"I have coached for 10 years, so within that, you do so many things that a manager would do anyhow, it's not a fantastically, unbelievable step."
Sunderland owner Ellis Short is busily drawing up a shortlist of potential candidates to replace Di Canio, but is in no rush to make an appointment as he attempts to get the right man.
But whoever does eventually get the job, Martyn McFadden, editor of fanzine A Love Supreme, insists it must be a man who can knit together a dressing room decimated during the death throes of Di Canio's ill-fated reign.
McFadden said: "We have got a position where we have got 14 new players and most of them have got little or no Premier League experience.
"We need to get an experienced manager who knows how to get the best out of these players, someone who knows how to handle the players.
"Some of these players need an arm around their shoulders, a bit of man-management as opposed to lambasting them and dismantling confidence."
Di Canio managed only three victories in his 13 games in charge and just two of them in the league, although the first, a 3-0 derby win at Newcastle, granted him instant hero status on Wearside.
McFadden said: "People will always be grateful to him for the fantastic day out in Newcastle we had and that's what made him initially so popular with the fans.
"The bottom line is he wasn't given long enough and that has angered some fans, but that's Ellis Short's decision."
Sunderland's next Premier League game against Liverpool is live from 3.30pm on Sky Sports 1 this Sunday.
Who should take charge at Sunderland?
Roberto Di Matteo