Alex Ferguson welcomed Henrik Larsson to Manchester United last night by declaring that the former Sweden international would have a huge role to play in the title race with his 10-week loan from Helsingborg coinciding with "the most important short period in this club's season".

Larsson, United's temporary number 17, has joined from January 2nd until March 12th and will be up among the highest earners at Old Trafford in that time. United say the deal is a straight loan arrangement, rebutting suggestions in Sweden that they have effectively had to buy the 35-year-old for around £350,000 with a pledge to sell him back when Sweden's domestic season starts again in March.

The striker made it clear yesterday the deal would not be made permanent. "The most important thing about Henrik is he has a tremendous goal instinct and I think that is part of his character that has always been there and is a great addition to our club," said Ferguson, who saw United's lead at the top of the Premiership cut to two points last weekend after his side proved profligate in losing 1-0 at West Ham. "That is the problem, seeing him go in March, but you hope by then he will have done enough to keep us at the sharp end of the competition.

"We will be sorry for that day to come but, in fairness to Helsingborg, we wouldn't want to intrude on their ambitions. We needed an experienced player. He may be here for a short period but that may be the most important short period in this club's season.

"Our standard of play has been very good but we have been missing some chances, like in Sunday's match. Hopefully the experience of Henrik and Ole Gunnar (Solskjaer) will make it decisive for us.

"When we announced it, a few of the players came to me and said: 'That was a good one, where did you pull that one from?' They were surprised by the secrecy that surrounded it. It has come at a good time. It looks like the championship race is going to go the whole road and people like Henrik could really help that."

Another of United's strikers, the France international Louis Saha, signed a one-year contract extension yesterday tying him to the club until 2010, though it was Larsson's arrival which caught the imagination. The Swede, formerly with Celtic and Barcelona, trained with his new team-mates yesterday and will return to Sweden for Christmas before reporting back at Carrington on January 2nd.

"I see it as a great challenge," said Larsson, who will make his debut in the FA Cup third-round tie against Aston Villa, managed by his former mentor at Celtic, Martin O'Neill. "It feels great but I understand how important it is to be here, it is an important time for United. It is quite a young team, they are really good."

He added that, if they keep playing the way they have been, they have every chance of winning the title.

"When I was at Celtic, my family and I were very settled and that was part of the reason why I didn't come down here at the time," Larsson said. "When I heard about this loan deal I thought this is a chance I couldn't say no to. I am 35 and there wouldn't have been another chance to join such a great club. But there is no chance I could stay on. It is a loan deal from January 2nd to March 12th. That is the time period I signed for. I know what I am here for and hopefully I can deliver."

Of coming face to face with O'Neill again next month Larsson said: "I had some great times with him in Scotland and I spoke to him and met with him when I was at Barcelona. I still talk with him quite regularly."