Rather like Sir Alex Ferguson's programme notes, Manchester United were less than convincing yesterday.
Ferguson did his best to reassure supporters that there would be life after Cristiano Ronaldo. 'They are concerned because they can't quite work out how we are going to compensate for all the goals Cristiano used to get for us,' he wrote before insisting that his side remained 'on the threshold of a very exciting era'.
Slideshow: brilliant Rooney celebrates his goal for United
But the supporters will judge for themselves and, while they have long learned to trust the finest manager in the game, this slightly stuttering performance is unlikely to ease the sense of anxiety, even if there were also key players missing, Rio Ferdinand chief among them, with injury.
There were reasons to be cheerful, and not just the three points. Wayne Rooney is thriving now that the more central role he so long craved is his. He followed a super equaliser against Chelsea at Wembley last weekend with the decisive goal here, in addition to delivering another first-class display.
But this was far from a stroll against newly promoted opposition, far from the one-sided encounter that was widely anticipated when Alex McLeish's team landed this as their opening fixture.
Quiet debut: Antonio Valencia
Had it not been for a more encouraging contribution from goalkeeper Ben Foster and a wonderful goal-line clearance from the outstanding Patrice Evra, Birmingham could have embarrassed the champions at Old Trafford.
They were pretty good, players like James McFadden, Lee Carsley and Joe Hart impressing enough to suggest they might not be the certainties for relegation some would have us think. Ferguson quite rightly acknowledged their efforts, which was more than he did for his own team.
His new boys did not exactly shine, Antonio Valencia giving a nervous performance that served only to highlight the loss of Ronaldo even more. He cost less than a quarter of what Real Madrid paid United for the Portugal winger but on this evidence, anyway, he looked like a quarter of the player.
Unlike Valencia, Michael Owen was not included in the starting line-up. He had to wait, instead, until the 74th minute to get on but a move that started with a long ball forward from Foster suddenly presented him with an opportunity to start the campaign in style.
He had only Hart to beat, but slightly snatched at a shot that was diverted wide by the young goalkeeper's outstretched left leg.
Killer blow: Rooney rams home his first of the season
In Rooney, however, United might now have one of the most influential players in the Barclays Premier League: a player who will relish the chance to step out of Ronaldo's shadow and become the talisman of this team - it was a little surprising he was not given the captain's armband yesterday, the honour instead going to John O'Shea - and guide them to an unprecedented fourth consecutive title.
Yesterday McLeish likened him to Zinedine Zidane and Michel Platini and, while the comparisons might not be totally justified, you can see his point. 'He is fast approaching real maturity,' said Ferguson of Rooney, which is good news for England as well as United.
He was terrific against Birmingham, forcing a fine save from Hart in the opening few minutes with a long-range lob and threatening again when Fabio Da Silva made a darting run down the right flank.
Foiled: Michael Owen was denied a goal by Joe Hart
He is, as McLeish explained, immensely difficult to defend against, the range of skills as well as the unpredictability of his game making him dangerous in a variety of ways.
His goal was pure predator, the manner in which he directed O'Shea's long ball forward out wide before then darting in to meet Nani's cross with a header that struck a post before he then seized on the rebound.
Birmingham then had their moments. Cameron Jerome sent a shot just inches wide and Franck Queudrue would have scored had Evra not been perfectly positioned to head the clearance away.
McFadden then forced a save from Foster, who did even better to deny Christian Benitez. After a nervous display, particularly with his feet, last week and his absence from England's friendly in midweek with injury, Foster will be heartened by his contribution on this occasion.
Off the mark: Rooney wheels away after his goal