It is a prospect that should strike fear into the hearts of Manchester United fans everywhere.

Not six months of abuse from City fans crowing about their first derby double since 1970, or even Sven-Goran Eriksson taking his record against Sir Alex Ferguson to three wins from three.

It is the fact their bid to emulate the Red Devils' Treble winners of 1999 could well rest on the shoulders of one man.

A man nicknamed 'Balsa Man' for his infamously fragile frame, who has become something of a figure of fun among the United faithful.

A man who in four years at Old Trafford has managed just 50 league starts, a figure exceeded by team-mate Nemanja Vidic in half that time.

A man who has managed the full 90 minutes just four times this season and managed to sustain an injury in the warm-up ahead of the game against Wigan in October. A man called Louis Saha.

For in the wake of United's 2-1 defeat in the Manchester derby, it is becoming increasingly obvious that United are short of options going forward.

That might seem strange given their tally of 50 league goals already, yet Ferguson's failure to bolster his frontline in January - other than the 'one for the future' signing of Angolan Manucho - could well end up costing him dear.

Despite the presence of the 27-goal Cristiano Ronaldo, all too regularly a United team shorn of Wayne Rooney looks powderpuff going forward.

It tells its own tale that the spiky Scouser is unbeaten in a United shirt this season - their four league defeats have all come in his absence.

Carlos Tevez looks a world beater with Rooney alongside him, but as a lone frontman - or with Ronaldo or Ryan Giggs pressed into service as an auxilliary striker - he packs a punch worthy of little more than a flyweight.

And when Ronaldo has an off day (usually in Rooney's absence, it has to be said), it is too much to ask youngsters Anderson and Nani to carry the burden of United's attacking threat, though the former has exceeded all expectations.

So with Saha on the sick list once again, the United bench for City's visit belied Ferguson's claim that his squad is the "strongest I have ever had", even before goals from Darius Vassell and Benjani had put the visitors 2-0 up.

Michael Carrick, Owen Hargreaves, Park Ji-Sung and Danny Simpson are all talented players in their own right but none can justifiably be considered a 'matchwinner', though the first of those did his best with a late goal.

So as United fans sought salvation from the bench in the way Teddy Sheringham and Ole Gunnar Solskjaer provided so regularly - and so famously - did in 1999, they were left to rue the continued absence of Saha.

For all his problems, and there have been plenty (ankle, calf, groin, hamstring and knee if you believe the reports) the Frenchman provides United with one thing they really lacked against City - something different.

His power and pace can break open any defence and his goals-per-game ratio isn't too shabby.

But Ferguson has simply been unable to call upon Saha with enough regularity for him to justify the continued faith that he has in him.

Of course, Rooney and Tevez may not miss another game this season, but the former is no stranger to injuries and suspensions, while the latter has looked fatigued in recent weeks.

All that takes nothing away from City, for whom derby day was memorable.

Their fans have been rightly praised for the respect with which they observed the minute's silence before the game - and the applause that rippled around the ground after their chant of 'One Frank Swift' late on told its own story.

On the field Richard Dunne and Micah Richards, plus Didi Hamann in front of them, adopted a 'thou shall not pass' attitude meaning Joe Hart was rarely troubled. And when he was - barring Carrick's late goal - he was up to the task.

Benjani's debut has earnt him a place in City folklore no matter how the rest of his career at Eastlands goes, while United right-back Wes Brown will have nightmares about the chasing he was given by Martin Petrov.

If they can maintain their performance level for the rest of the campaign, European football next season looks to be on the cards.

That is far from a given, though, as City remain consistently inconsistent - only two weeks ago they couldn't beat rock-bottom Derby just days after crashing out of the FA Cup at Sheffield United.

But for now - to the delight of their fans - the bragging rights are theirs.

The inquest is under way at Old Trafford, though, with United fans hoping Ferguson won't be left to rue keeping his chequebook locked away in January.