When Hull City visited Old Trafford last season, the striker was a man on his own mental plane, rampaging uncontrollably around the pitch in that mood which sometimes takes him, to end the match booked in a 4-3 win.
When the same Hull played Manchester United on Saturday, he was back on a different level of his own, scoring all four goals before leaving the pitch with a Tigers’ shirt tucked into his shorts and Sir Alex Ferguson in little doubt that he has the finest striker in the country on his hands.
Ahead of tonight’s Carling Cup semi-final second leg showdown at Old Trafford, Ferguson muttered darkly that he believes Real Madrid are trying to inveigle their way to his signature.
“I think we know where that is coming from,” he said. “In fact, we are sure where it's coming from. It's not his agent. It's not Wayne. So, we'll deal with that.”
He won't be losing any sleep over the Madrilenos this time around, though, because while you always knew that Cristiano Ronaldo would head back to the sun one day, Rooney has never displayed the slightest inclination.
Contract negotiations will begin this summer, but you sense that Rooney is a player so wedded to his own game at periods like this that he probably doesn't even know that his current deal expires in two-and-a-half years' time.
If the Spanish have read about that £500m bond issue of the Glazers and got covetous, they've forgotten that the simmering antipathy felt towards the Americans would burst into full-blown revolt if Rooney, the heartbeat of Manchester United at the age of 24, becomes the latest to service the balance sheet.
It had always seemed that Rooney would be the major beneficiary of Cristiano Ronaldo's departure last summer, freeing him as it did from the yoke created by the Portuguese's reluctance to do any heavy lifting.
The transformation from “someone who could be great” into “someone who is a great player” — the aspiration Rooney spoke of last summer — has been remarkable.
“I think he has become more aware of the penalty box,” Ferguson said of Rooney.
“Playing in that direct role has given him the appetite to be in the box more of the time. He still has moments when he goes to other areas of the pitch, but it's about choosing those moments more maturely.
“I think the main reason he is scoring more goals is because he has been in the right place at the right time. That's what goalscorers do.
“I don't think he is becoming more selfish in those situations. He is realising that, as the main striker through there, he is threatening all the time, so he is getting the rewards for that.”
Roberto Mancini is understandably less affectionate. It was put to him yesterday that Rooney — whose performance eclipsed that of Carlos Tevez in the League Cup semi-final first-leg — was the man to shut out tonight.
“I hope that Rooney scored all his goals last Saturday,” he replied. The accompanying laugh was a nervous one.
Ferguson will be far from happy with the Football Association's decision yesterday to charge Rio Ferdinand with violent conduct for apparently striking Hull's Craig Fagan in the face on Saturday.
The defender, who had just returned after three months out, will be available for tonight's game because the FA will not sit in judgement until tomorrow, though if he pleads guilty by today's 6pm deadline he will be began a ban immediately and miss Sunday's visit to Arsenal.
And he will hope to have Ferdinand to bring calm to his defence in a game that Ferguson accepts will be highly charged.
Nine thousand travelling City fans add even more to the mix and both the FA and Greater Manchester Police have already stepped in with their own pleas for calm.
Ferguson has no fears for his own side. Having been through so many big nights in the past, the Scot feels there is no need to be worried.
“I don't pay any attention to all that,” he said.
“The player behaviour has always been perfect. We have great players who play to the right rules of the game.
“We have never had any issues in big games. Look at the record. I am not worried about it.
“The fact it is a local derby is an important enough incentive, but we have already shown we want to be in the final. We have played against some great teams in similar situations over the years.”
One interested spectator in south London will be Fulham defender Chris Smalling who, after only nine first-team appearances for the Cottagers and less than two years after being plucked from total obscurity at Maidstone United, has snubbed Arsenal and agreed to join Ferguson at Old Trafford.
It represents a moral victory for United, who lost out to the Gunners in their pursuit of Aaron Ramsey from Cardiff two years ago.