Roberto Mancini has raised the spectre of Owen Hargreaves facing old club Manchester United at Old Trafford next month.
Three years of simmering resentment at the way Hargreaves' long-term knee injuries were initially handled by the Red Devils medical staff spilled over this week.
In the aftermath of his goalscoring debut in City's League Cup win over Birmingham, Hargreaves claimed he felt "like a guinea pig", such were the treatments he was forced to undergo.
To Hargreaves, the whole problem had been exacerbated by injections he was advised to have by United as part of his attempts to combat a tendinitis problem that first came to light in 2007, when he was still at Bayern Munich.
Evidently, Ferguson, and United, are unhappy with the 30-year-old's observations, their staunch rebuttal merely fuelling what was always likely to be a high-octane duel on October 23, which Hargreaves could be at the centre of in more ways than one.
"We have to be calm and think about his body," said Mancini.
"If everything is okay in the next two or three weeks, maybe he can play against Manchester United."
Such a prospect is enticing given Hargreaves' history, although it seems unlikely he can expect a warm welcome from a club he only managed to get on the field for for a grand total of six minutes for since September 2008. "United does not acknowledge any validity in the comments Owen is alleged to have made," said a United statement.
"Manchester United is disappointed with Owen's remarks. The club gave him the best possible care for three years and is as disappointed as anyone he was not able to play a part in the team's success at that time.
"It has shared all the medical records with Manchester City and is comfortable with the actions taken by its medical staff at each step of his many attempts at rehabilitation.
"Manchester United has some of the best sports medical staff in world sport, who have made a significant contribution to United's on-pitch success in recent seasons."
Earlier, Ferguson was adamant any criticism of his back-room team was completely without foundation.
"Do you think we would be successful if they were not 100 per cent brilliant? Our doctor and his five physios are fantastic -- that is my opinion and that is more important than what anyone else has to say about it," the Scot said.
Hargreaves underwent surgery on both knees during the 2008-09 season.
Remarkably, after so long on the sidelines, and an attempted comeback against Wolves last November which he knew was going to be a disaster when he went out for the warm up, the Calgary-born star has achieved full fitness barely three weeks since joining City.
"I received some injections but my tendon was never the same," he said.
"I tried to get back on my feet and they said my tendon was good, but it felt like I was made out of glass.
"I've had to be a guinea pig for a lot of these treatments.
"I wanted to play. Everyone wanted me to play, so it's not really an option to say, 'sit it out and rest for six months'. With hindsight it's a lot easier, but I wish I had not had the injections."
Aware of the delicate nature of the matter, City manager Mancini opted to tiptoe carefully through the row, although he confirmed Hargreaves is now pain free.