Manchester United's Robin van Persie celebrates his goal against Sunderland.

Dublin – The talk will always shape towards Robin van Persie, a player about whom Martin O'Neill had no compunction in saying late on Saturday that he is Manchester United's Lionel Messi and whose decision to take his boots to Old Trafford rather than the Etihad gave Sir Alex Ferguson's club a “psychologically massive” boost, as the Sunderland manager sees it.

O'Neill sees no danger in United being so dependent on one player, whose 15 goals represent more than a quarter of the club's entire season's haul in all competitions and who scored their first in Saturday's 3-1 home win over Sunderland. Henrik Larsson had the same kind of impact for the Celtic team he managed from 2000, he agreed. “[Van Persie] can get goals out of very little. It looks like nothing is happening, you have players in the area, but all of a sudden he has opened up a gap,” O'Neill said. He reflected that sometimes football all boils down to having a talisman like that. “Would Barcelona have the same effect if Lionel Messi didn't play? They are a very talented team, but without him you don't know, because Messi is their talisman.”

But there was a subsidiary story, too. Reclaiming the title will be about more than Van Persie's goals and, on an afternoon when United failed to improve on their record of four clean sheets by conceding to another aerial attack, Phil Jones' first Premier League start of the season slipped by almost without notice. It should not have done.

We learnt a little more about why Jones shushed the Manchester City fans after the derby win – “the substitutes were getting a lot of stick from the City fans behind the dugout,” he revealed – yet his overriding motivation is to set back on track Sir Bobby Charlton's grand comparisons of him with Duncan Edwards. That proclamation, only a year ago, seems a little dated now.

Jones was also asked at the weekend about the perception that he might be a future United captain. “It sounds great and it's nice if people think that one day that might happen, but there is a long way to go,” he said, which is right. After that very encouraging start last season, back and knee injuries have set him well back.

The right-back role Jones was given against Sunderland was by no means his preference, even though Fabio Capello assigned it him in the pressure game at Podgorica when England sought European Championship qualification two years ago. But he reminded us what a mobile and aware player he is – driving forward, ready to give and go, assured enough now in this company to demand the ball back and be frustrated when he doesn't get it.

At times, he and Antonio Valencia were operating so close together on the flank they shared that the Ecuadorean looked redundant and Jones was at the hub of the excellent first half-hour's football. More defensively solid than Rafael – who still often looks headless, whatever all the current admirers might say – Jones burst out into his natural midfield territory, too. His place at the nexus of a cross-field move was overlooked amid the early havoc United wreaked.

The momentum of interchanged passes with Tom Cleverley took Jones out into midfield, to thrust another clean pass first time to Ashley Young and race for the return ball that didn't come. Jones doesn't make it look effortless. He's always red-faced with endeavour. He appeared to pick up a knock in that first period, and never quite scaled the same heights in the second. As he sustained a knee injury on his second day back in pre-season training after a back problem, consolidation will take time.

The same goes for another of England's hopes, Sunderland's Adam Johnson, who was invisible. “Where he is having difficulty is that, at [Manchester] City, he was coming on with 25 minutes left and having little cameo roles,” O'Neill said. “With us, he is having to start the games with a lot of added pressure, naturally.”

O'Neill, who did not dismiss out of hand the idea of Fraizer Campbell leaving in January, is living with the consequences of a fiscal squeeze, after the boom days of Steve Bruce, and it is an austerity which leaves his side facing an end-of-season downgrade. There were extenuating circumstances for this defeat. O'Neill's only two functioning full-backs were injured, for instance, and his squad is pitifully thin. But on this evidence it looks like things will be touch-and-go.

That's why it was so magnanimous of O'Neill to discuss Van Persie, a talent currently beyond his dreams. The Dutchman's decision to play in red not blue will, fitness permitting, define who takes the title, O'Neill believes. – The Independent