At half-time yesterday the message board on Manchester United's official website could be described only as democratic. When it came to blame, just about everyone connected with Old Trafford got their fair share.

The defence, the midfield, the management came under fire but probably the most pertinent message asked "What is going on?" At precisely the same moment, Sir Alex Ferguson was saying something similar in the City of Manchester Stadium dressing rooms, and the hairdryer would have been blowing at its fiercest in the direction of the back four.

What was going on, as far as Ferguson was concerned, was some of the most inept defending this side of a struggling Sunday pub side, and at least they would have the excuse of a heavy Saturday night. United had no such alibi, and they have been looking for one since August.

While Chelsea and Liverpool have been building their Premiership challenge on defences that would make a cash-strapped Chancellor of the Exchequer look generous, United have been swaying around on top of dodgy foundations all season. It is a failing that partly cost them a place in Europe and yesterday it knocked them out of the race for the title. At Manchester City of all places.

"We looked like a team who were up for a derby match and up for a scrap," Stuart Pearce, the City manager said, and that was precisely what was wrong with the United defence yesterday. When it came to a physical challenge it was usually a player in a sky blue shirt who prevailed. And given that it was the muscles of Darius Vassell (5ft 7in), Trevor Sinclair (5ft 9in) and Andy Cole (5ft 10in) that were being flexed, you can gauge how pathetic the red leviathans were. Gary Neville had a mediocre game by his standards and was still head and shoulders above his defensive colleagues.

With the first City goal, John O'Shea was dispossessed, Neville could not clear his lines with a header and the centre of the defence disappeared. In the second, Mikaël Silvestre attempted to halt Vassell in much the way ushers guide wedding guests to their seats. "Which side sir?" To the left of Edwin van der Sar will do nicely, thank you.

Where was Patrice Evra, United's new left-back, in all this shambles? It was a question that Ferguson would have been asking, had he not been wondering where he had put the £5 million receipt just in case Monaco would take back faulty goods. The answer was: missing.

Described as "one of the best full-backs in Europe" by Ferguson, Evra is undoubtedly quick, but even his fleet-footedness could not match the speed of the United supporters in wondering whether he is going to be up to the physical challenge of the Premiership. The small Frenchman looked overwhelmed, was dominated by Sinclair, and was replaced after 45 minutes with his side two goals down.

"Maybe playing him was a bit of a gamble," Ferguson conceded. "That's why I played Mikaël Silvestre, because he is French and could look after him." Which explained mistakes one and two. As for the substitution, the United manager added: "At 2-0 we had to make sure we didn't concede another goal and John O'Shea is more used to derbies." That takes care of mistake No 3.

"It wasn't Evra's fault," Ferguson said. "The defending was poor. We gave the ball away too often and couldn't deal with crosses into the box." Apart from that, everything was perfect.

Ferguson was describing the first half but the apex of inefficiency came after 75 minutes when a high ball caused so much confusion for Silvestre and Rio Ferdinand that you wondered if the Chuckle Brothers had been slipped on as substitutes to form a centre-back partnership. It would have been funny if you had not considered the £150,000 in wages that supporters are forking out for these two every week.

The only one connected to United who had reason to laugh was Nemanja Vidic, who can now make his debut after his £7m transfer safe in the knowledge he can only make things better. He could not be worse.