Captain Nemo may have had 20,000 leagues to contend with but keeping your head above water in two is difficult enough. The mere sight of Highbury's marble hall will be sufficient to remind Ferguson of that this afternoon. When he last entered the home of the Arsenal, 10 months ago, his team were riding high in the Champions' League with four wins out of four. He departed with the taste of a 3-2 defeat, served by a side whose fresher appetite was to prove decisive in the Premiership when United found themselves with a little too much on their plate.
This is the fourth time in five seasons that Ferguson has fought concurrent league campaigns at home and abroad. And only once before has he managed to steer his club through twin fixture lists to the top of either pile. That was the season before last, when United emerged with the prize now on display at Highbury - or on loan, perhaps, as page 46 of Wednesday's match programme inferred. The Premiership trophy was pictured in an advert for the Old Trafford Museum, with the headline "Missing" and the message: "Will the holders polish and return within nine months." There was no question mark.
The very least expected of Ferguson from his 13th season at Old Trafford is a fifth domestic league success and it will take rather more than this afternoon's 90 minutes in London to suggest whether he will duly deliver it. Beyond Highbury today, United have the small matter of a neighbourly affair with Liverpool at home on Thursday, followed by a trip to Munich (their first for a competitive match in the city that will forever be synonymous with their name) and the annual, traditionally pointless, trek to the Dell - all within the next fortnight. The immediate horizon would have been clouded enough for Ferguson without the additional complication of his place in the longer-term scheme of things at Manchester United being up in the air, and not yet assuredly in the Sky.
The visit of Barcelona for United's opening Group D fixture in the Champions' League probably even had him pining for the good old days of four years ago, when his chief concern going to the Nou Camp was how to shuffle his pack to comply with the five foreigners' ruling. Ferguson may have played a poor losing hand that night, gambling without Peter Schmeichel and Eric Cantona, but at least he dealt it himself. The poker-playing within Old Trafford's corridors of power lately could hardly have helped him apply his mind to the task of taking three points off Barcelona on Wednesday.
The distraction was clear on Tuesday, when questions arising from Sky's proposed pounds 623m takeover were posed at his eve-of-match press conference. Reports of a move by Rupert Murdoch's men for the Japanese midfielder Hidetoshi Nakata (an obvious attraction for News Corporation's Star TV audience in the Far East) were dismissed as "rubbish", though later substantiated in Italy, where Nakata plays for Perugia. And stories linking Ferguson to the vacancy that will materialise at Juventus when Marcello Lippi retires, though addressed with some irritation, were - significantly - not denied.
At 56, and having recently remarked "I am coming to the last lap of my life", Ferguson is unlikely to uproot from Sir Matt Busby to launch a new career with the club whose name literally means "youth". His heart obviously lies at Old Trafford, where his pursuit of United's holy grail, a second European Cup success, remains frustratingly unfulfilled. He has, however, clearly been unsettled by recent events. At the very least, the Sky-high valuation of Manchester United has made him reassess the worth of his contribution - and to conclude that, at pounds 600,000 a year, it ought to be closer to the pounds 1m George Graham commands at Elland Road.
It is obvious, too, that Ferguson did not take kindly to being denied knowledge of the takeover bid. With ironic timing, the Alex Ferguson Story, screened by ITV on Tuesday night, revealed how in 1969 he telephoned home from a pre-season trip to Scandinavia to discover that Rangers had released a statement saying he was no longer wanted at Ibrox. "He was really, really upset because nobody from the club had spoken to him," John Grieg recalled of the distraught colleague he encountered in a hotel lobby, drunk and raging in bright red pyjamas.
It was a more sober, and more soberly attired, Ferguson who took his customary elevated pitch-side berth at Old Trafford on Wednesday. Given the events of the past fortnight, he might have been relieved to find the Jaap he bought in the summer, and not the one the Murdoch men want to buy for him, in his team. He would certainly have been delighted to see his players, clad in white, look the Real thing for half an hour. David Beckham and Ryan Giggs were simply dazzling. By half-time, though, after sitting back in the closing 10 minutes to invite the turning of the tide that followed, United were already phantoms of their former selves.
By the final whistle, having turned a 2-0 cruise into a 3-3 white- knuckle ride, they had stirred the ghost of the 4-0 nightmare in the Nou Camp. It was the first time since that November night in 1994 that United had conceded more than two goals in a European tie. It could have been worse. Peter Schmeichel's goal led a charmed life in the final 20 minutes and television showed that Barcelona were unfairly denied a goal by a linesman before half-time. "We should have won," Louis Van Gaal, Barca's coach, lamented. "I am a little bit angry with my players."
It was fair to assume that the human hairdryer was functioning in the home dressing-room afterwards but the fact that Ferguson reserved his public anger for the referee at least confirmed that the manager remains, amid the Old Trafford turmoil, his fiery old self. Unlike Van Gaal, who ignored the goal that got away ("It is always the decision of the referee and I don't argue"), Fergie breathed his verbal fire and brimstone at Signor Braschi. "The referee was a real shocker," he said. "I saw the Barcelona president go in to see the referee after the game. I'm sure he'd be delighted to see him."
When Ferguson finally headed homeward he no doubt checked every grassy knoll on the way. His mind, however, has since turned from conspiracy theories to the Gunners who will be lying in wait for his beloved Manchester United today.