When Sir Alex Ferguson starts going a stroppy shade of pink and reverts to sarcasm as his most withering form of attack, then it's safe to say that Ol' Taggart is also just a wee bit rattled.

So while, with irony, he can pronounce Manchester United's current position - two wins over ordinary opposition away from his 10th Premier League title and just 90 minutes from the Champions League Final - as a "disaster", he still can't mask his alarm that United's season, once a Rolls Royce smooth ride, could start careering off into De Lorean territory at Old Trafford tonight.

A jittery loss at Chelsea, his players' ugly bust-up with groundstaff afterwards, injury fears over key men Nemanja Vidic and Wayne Rooney and the seeming evaporation of United's domineering air are all reasons enough to be fearful of the arrival of a Barcelona side who hinted in their goalless first-leg encounter at the Nou Camp last week that they're capable of inflicting a familiar torment on Fergie - death by a thousand passes.

Yet what must gnaw away most at the United boss is how it always seems to be around springtime in the biggest club competition of all that his teams get found out. Yes, he'll always have Barcelona '99 and the greatest European Cup story ever told but as he reiterated again yesterday: "This club should have had more success in Europe."

For if there's the flimsiest stick with which to beat the most bemedalled manager in English football annals, it can only be Fergie's Champions League stutters. "It's ridiculous this club's only won it twice," he grumbled before Christmas. In his perfectionist's mind, it's also ridiculous that he's lifted it just once in 13 previous attempts with United.

To anyone else, once would be the ultimate; to Ferguson, it's like a nagging reminder of each subsequent failure which keeps spurring him on at 66.

So he makes no apologies for sending out a half-baked team last weekend.

"I wanted to give them the very best chance," he said, at a stroke making Europe sound infinitely more important than another domestic bauble.

To Ferguson, three semi-final, four quarter-final and three other knockout stage defeats in the last 11 Euro seasons must represent his greatest personal disappointments, particularly because of the emphatic manner of his teams' demise.

For while reflecting yesterday on how United had been "unlucky" in semis against Borussia Dortmund and Bayer Leverkusen - claims which don't bear much scrutiny - there was nothing fortunate about how Milan dismantled them at the same stage last year and also two years before in another knockout tie.

Then there was Real Madrid outclassing them in both the 2003 and 2000 quarter-finals. Ditto, Bayern Munich in the last eight of 2001. Ferguson's Manchester United don't do inferiority complexes; yet these European nights came closest to instilling them.

It couldn't happen again, could it? Ferguson looked at a side with stellar talent like Lionel Messi, Thierry Henry, Samuel Eto'o, Deco and Xavi and recognised how Barcelona would be the same old Barca "trying to get you on that passing carousel, trying to get you dizzy".

Defensively, United fortunately didn't get giddy enough in the Nou Camp to be punished by an attack currently so blunt that Barca have failed to score in their last three matches and have managed to win only one of their last nine La Liga games.

Yet even so, such was their technical superiority over United last Wednesday that coach Frank Rijkaard was encouraged to feel they had rediscovered a confidence which would keep United chasing shadows again tonight.

"I am sure United will come out more to attack than at the Nou Camp. The keys to the tie? We need to impose our style, to worry only about our play, not United's," reckoned Rijkaard.

No wonder Ferguson preaches "patience" with his lot up against the greediest monopolisers of the ball in the competition. On average, they can boast 58 per cent of the possession per game.

It seems odd but, for all Ferguson's evident feistiness, he still cut a less bullish figure at Old Trafford on the eve of the match than the normally phlegmatic Rijkaard who, surely knowing that elimination tonight will give him nothing to look forward to except the sack, was the one on the psychological offensive.

While Ferguson was uncharacteristically fretting aloud that "to be honest, a lot of things worry me" about the match, Rijkaard was busy psyching out the one thing that worries him most, Cristiano Ronaldo, by musing aloud how his missed penalty last week would haunt him if United failed tonight.

Not as haunted, though, as Ferguson himself could end up feeling after a couple of critical matches in which conservatism and safety-first instincts have straightjacketed him.

Rijkaard promises to be brave and true to his attacking principles tonight - look out for him gambling with a start for Henry - but the same must apply to his illustrious opponent. So, no more 4-5-1. No more caution. Fergie has to fire Ronaldo and his tiring troops into reimposing their swagger, dictating the pace and flowing forward like the magnficent, swaggering bullies they were for so much of the season.

Otherwise, just like last year, that outlandish idea of the first all-English Champions League Final may just have to be shelved to some other May day.