Is Mancini capable of delivering the goods?
Martin O'Neill of Sunderland versus Roberto Mancini of Manchester City has the allure of a major battle of wills at the Stadium of Light on Sunday afternoon.
Most would bill the affair as a collision of heavyweights.
But is Mancini, the boss with greater resources than any of his rivals, flattered by such a ranking?
Liam Brady, who knows Serie A better than most Italians after winning Lo Scudetto twice with Juventus and also enjoying distinguished service with Sampdoria, Internazionale and Ascoli, has said he suspects so.
It is a bracing assessment, to say the least, when you consider Mancini's managerial track record at home (three titles, six Italian Cup triumphs) and the fact that his current charges share leadership of the Premier League after last season's breakthrough triumph in the FA Cup.
But then Brady has never been known to punch less than his intellectual weight in assessing a game in which he performed so superbly, and who can say that the mostly agreeable Italian -- if you don't happen to be Carlos Tevez -- is not still faced with some biting questions?
The most penetrating one was implicit in Brady's doubt that Mancini has evolved an authentic approach to the game, that he has been able to bring all of his knowledge and experience -- he too was a player of outstanding talent who won two Scudetti, with Sampdoria and Lazio -- into consistent leadership at a top club.
Mancini's admirers point to his hat-trick of league titles with Inter between 2006 and '08.
His detractors are equally eager to point out that the achievement was helped immeasurably by the match-fixing scandal that devastated Italian football.
They also point out that Mancini lost his job at Inter because of exasperation over his serial failure to make any impact on the Champions League, one that he has reproduced this season with his inability to get the better of Bayern Munich and Napoli in the group phase.
At Sunderland, the test is quite basic. After sustaining a first league defeat at Chelsea, and then failing to score at West Brom last Sunday -- results which came either side of a somewhat fraught home victory over Arsenal -- can Mancini return his team to the imperious mood they displayed in the early season blitz which brought overwhelming victories at White Hart Lane and Old Trafford?
It is surely the cue for expressions of virtuosity -- and freedom -- from such outstanding talents as Sergio Aguero and David Silva against Sunderland. No question, Mancini has impressive human resources -- but does he have the knack of injecting the necessary will, and confidence, when it matters most?
Certainly City, no less than the manager, continue to exhibit more than the hint of a split personality.
After the frustration at West Brom, Mancini talked of the need for quicker passing. In the tighter corners he invariably reaches out for a technical explanation for a lack of progress. Sometimes it seems that the tactical blackboard is as much a tool of personal defence as a springboard for creative inspiration.
It means that there is still a sense that for all this season's progress -- and some brilliantly devastating football in the opening phase -- Mancini remains some distance away from the swagger and the invention of his two closest Premier League challengers, Alex Ferguson and Harry Redknapp.
Redknapp, the Tottenham manager who delivered such a blow to Mancini the season before last when he edged him out of the Champions League spot that the wealth of City owner Sheikh Mansour had, in many minds, virtually guaranteed, has built what looks like an authentic title challenge with absolute consistency.
There have been no tactical compromises at White Hart Lane. A superbly inventive midfield containing Luka Modric, Rafael van der Vaart and the explosive Gareth Bale, and secured by the reliable presence of Scott Parker and Sandro, has been invited to do what comes naturally game after game.
By contrast, we have seen the eruption of City into an aggressive mode that could not have been imagined before the arrival of Aguero at the start of the season.
Before that City were, apart from the virtuosity of Silva and the power of Yaya Toure, thoroughbreds firmly on the bridle.
When Aguero exploded in his first match -- as a substitute against promoted Swansea -- it was an intervention that seemed to change everything.
Last season Mancini and his senior players were emphatic. Champions League football was the main priority and for this achievement the key word had to be caution.
It is true City found a degree of expression in their FA Cup success, but there was still that powerful sense of a team mostly playing within itself.
Aguero made nonsense of this with the sweet alliance he immediately formed with Silva, who in the first half of this season announced himself a runaway favourite for Footballer of the Year.
When you saw Aguero score with brilliant conviction, then combine with Silva for an even more spectacular goal, it was hard to imagine this work was on behalf of the team who had spent much of the previous season pulling down shutters and slamming doors.
Mancini went to such places as the Emirates and Stamford Bridge without pretence. He was there for the point. He hauled some of the league's most expensive players behind the ball.
When United came to visit, it was City who looked as though they were fighting for a foothold on some foreign field.
The defence for such cowering caution was that City were involved in a project that could only be accomplished in various stages. Now it is utterly redundant, which means that on Sunday no-one can any talk any more about the long-term aims of the project.
The project is now -- and at its heart is the question Brady posed. Is Roberto Mancini really the man to get it done?
Surely, we will know soon enough.