SOCCER: Manchester United will spend the New Year in familiar territory on top of the Premiership - but a single sentence from skipper Roy Keane highlighted the fear gnawing away at Old Trafford.

Even the loss of Darren Fletcher to a hotly-disputed double yellow card could not halt United's title march at Middlesbrough on Sunday.

Alex Ferguson's side cruised through the final half-hour with barely a scare to end a run of successive defeats at the Riverside and pile the pressure on chief championship rivals Arsenal.

Yet in the 10 days before the Premiership champions resume their league programme at Bolton, Ferguson will be busily finalising his plans for the January sales.

Time and again the United manager has highlighted the difficulty in luring the players he wants to the club midway through the season. But, as Keane pointed out after Sunday's 1-0 victory, failure to bring in at least one new striker will place a massive burden on the man his club cannot afford to be without.

"Please God nothing happens to Ruud van Nistelrooy, because maybe we are not as strong up front as people think we are," said Keane.

"The spirit amongst the squad is outstanding, but I still think we could do with another one or two players.

"When you bring someone in, it gives everyone a lift, and I know myself from when the manager buys a midfield player it makes you step up another level.

"The manager is always looking at the bigger picture, but squad-wise we came up a little bit short last year."

Ferguson has already indicated his intention to bring in a new striker to take the pressure off free-scoring van Nistelrooy, who remains on 17 for the season after drawing a rare blank against Middlesbrough.

If weekend reports suggesting Diego Forlan could be offloaded in any deal to bring veteran centre-half Gareth Southgate to Old Trafford are to be believed, then Ferguson has probably set his sights on two purchases when the month-long transfer window opens on Thursday.

Ideally, both will be free to add weight to United's Champions League campaign, emphasising the attraction of Mark Viduka and Louis Saha, who have been linked with a move to Old Trafford recently.

Leeds and Fulham have been vehement in their claims that neither player will leave their current home, but the cash-strapped Elland Road outfit in particular may find it difficult to turn down a big-money offer.

West Ham's Jermain Defoe has also been mentioned as a potential target, although Ferguson will face stiff competition from title rivals Chelsea and Arsenal for the £6 million-rated England Under-21 international.

The impending return to fitness of Ole Gunnar Solskjaer, who will have missed four months of the campaign following a knee operation when he makes his reserve-team comeback in the middle of next month, should at least allow Ferguson some flexibility in his team selection.

But most United fans shudder to think what would happen to their team if van Nistelrooy were to pick up a long-term injury.

"While Ole is still injured it would be a problem, because we like to have Ruud up there by himself," Ferguson admitted to MUTV in a pre-Christmas interview.

"But for a period we also played Diego Forlan alongside Ruud and while it was a difficult decision to leave Diego out when I changed it back again, the goals he got during that time have given him the confidence that he could score in our team.

"The alternative would be for Diego to play up front on his own, with Kleberson, Paul Scholes or Ryan Giggs in behind."

While there is no doubting Forlan's improvement over the past 12 months, few believe he would be able to carry United's attack on his own for any length of time.

It appears Keane shares those sentiments, which is why he is imploring his manager to take action on Thursday.

"We are quite happy with the way things are going, but the time we really want to be top is in May when the trophies are being handed out," he said.

"We have played well in patches and generally we have got stronger in the second half of the season, although you can't afford to look at the history books.

"It's what we do this season that counts now and there is still a long way to go yet."