Ferguson faces a race against clock to find firepower

After failing against Burnley, United will know Rooney needs greater support. Sam Wallace on the options in the current transfer window

The last few days of August are a damned difficult time to buy a good striker, not least one that promises to transform your season, and Sir Alex Ferguson will reflect that the occasion he acquired Eric Cantona in the space of one phone conversation was a once-in-a-lifetime moment.

There can be no doubt that Manchester United have a problem with their strikers because there is something wrong with a United front line that cannot score away at Burnley, let alone only one at home to Birmingham City. Ferguson's issue is whether, post-Cristiano Ronaldo, the problem is temporary – fitness, confidence, form – or something more serious that needs to be fixed quickly.

The defeat to Burnley on Wednesday night was one of those appalling results for United that have occasionally blighted them even in their last 17 years of pre-eminence. For all the quirkiness of the evening at Turf Moor, similarly bizarre defeats have befallen United in the past when inferior opposition such as Wolves (2004), Bolton (2001 and 2002) and Derby County (1997) have scored precious wins over them in the league.

It is hardly a crisis – although in modern football a big four club is only ever two defeats away from one – but there is a more fundamental question: are United's strikers good enough for the job? There is nothing much wrong with Wayne Rooney but the displays of Michael Owen and Dimitar Berbatov would test the faith of any manager with 12 days left of the transfer window.

As a result so much now rests on Rooney and the goals he scores. It should be remembered that in his first two seasons at the club Rooney outscored Ronaldo comfortably and in 2006-2007 they both scored 23 goals. Only in Ronaldo's two final seasons at United did he significantly overtake Rooney, scoring 68 over the two years to Rooney's 38.

But take out Carlos Tevez's contribution too – 34 goals over two seasons – and you can see why there is an added danger of Rooney's frustration getting the better of him. On Wednesday night he slammed a boot down on Tyrone Mears as he felt the game drifting away from him; the only improvement in his temper tantrums is that these days he recovers in time at least to look apologetic.

Ferguson has only ever really spent big late on in the transfer window when the player has been a summer-long target such as Berbatov or one who has become available earlier than expected. This was the case with Rooney in 2004, when Ferguson rightly spent the entire next summer's budget, and Ronaldo a year earlier when it became clear that United might miss out if they left him at Sporting Lisbon a year longer.

In short, the approach to transfers of Ferguson and Unied's chief executive, David Gill, has always been the model to which other clubs have aspired: discreet and quick, with less of the friction with the selling club that seemed to affect Gill's predecessor, Peter Kenyon. Since Ronaldo's departure the expectation has been, despite Ferguson saying otherwise, that he has a transfer up his sleeve.

The options across Europe, however have looked pretty bleak, Having to wait until Real Madrid and Manchester City did their business to avoid being caught in an auction did not make it any better. The ease with which Real Madrid took Karim Benzema from United was shocking. The acquisition of Gabriel Obertan from Bordeaux showed the limits of the market – currently injured, he was farmed out on loan to Lorient by Bordeaux last season.

Samuel Eto'o has been transferred already, so too Klaas-Jan Huntelaar, although he was watched closely and not judged to be at United's required level anyway. Franck Ribéry, David Villa and David Silva look to be unavailable for another year. Sergio Aguero is cup-tied for the Champions League, as is his team-mate Diego Forlan, who would be an intriguing returnee to Old Trafford.

The prospects of United going back over their options now would be bleak simply because what they really need is a ready-made striker who can hit the ground running. Of all those who has defied the odds to stay at his club this summer, Edin Dzeko is one of the most interesting. He was Wolfsburg's top goalscorer last season when they won the Bundesliga and somehow they have managed to keep him, despite the interest from the likes of Milan.

So too the Roma striker Mirko Vucinic, but none of these players would reflect the United way of doing things, which is to identify their targets early and pick them up quickly once the transfer window opens. It does the beg the question as to why, if United expected to lose Ronaldo and Tevez this summer, in January they did not challenge for Jermain Defoe, a player they have looked at before.

Striking problem: Three who could rescue United

Edin Dzeko (Wolfsburg)

But: The German champions have rejected all bids this summer.

Mirko Vucinic (Roma)

But: Sold Aquilani to Liverpool, reluctant to let any more stars leave.

Franck Ribéry (Bayern Munich)

But: £80m valuation for the sought-after winger – a long shot.