Nemanja Vidic will link up with his Manchester United team-mates this morning after having his work permit granted.
Sir Alex Ferguson has made Vidic the first major signing of the Malcolm Glazer era by splashing out £7million on the Serbia defender.
The 24-year-old, who has signed a four-and-a-half-year contract, was due to arrive in England last night and was expected to train with United for the first time today.
However, given the short time scale and his lack of match practice since the Russian season ended in November, the former Spartak Moscow star is unlikely to be involved in Sunday's FA Cup tie at Burton Albion.
Although Vidic impressed with Spartak, it is his performances for the Serbian national side which brought him to Ferguson's attention.
Vidic was part of the Serbs' `Famous Four' defence which conceded just one goal in qualifying for next summer's World Cup in Germany.
Ferguson said: 'I am delighted the two clubs have come to an agreement. Nemanja is a quick, aggressive centre-half and at 24 will be a terrific addition to the squad.'
The manager told MUTV: 'As I keep pointing out, good defenders win you things,' Ferguson told MUTV.
'In my time we have had people like Steve Bruce, Gary Pallister, Paul Parker, Denis Irwin, Ronnie Johnson and Jaap Stam.
'This lad is really natural and athletic. I know you need good defenders and that is exactly what this lad is.'
If Vidic is not involved in the Burton tie, he could get a run out in a reserve team fixture against Leeds on January 12, putting him in line for a potential Premiership debut against Manchester City the following weekend or Liverpool on January 22.
United are also hopeful of winning the battle with Inter Milan to sign Monaco full-back Patrice Evra.
The French international, whose arrival could signal the end of Mikael Silvestre's Old Trafford career, has been axed for tonight's French league clash with Auxerre.
Monaco are now resigned to losing the talented defender but are holding out for their £5million asking price.
Inter are thought to have offered £3.5million and, while United have yet to make a move, it seems only a matter of time before Ferguson lodges a formal bid.
Meanwhile United have vowed to play fair if they make a move to sign Benfica winger Simao Sabrosa, according to assistant coach Carlos Queiroz.
The Portugal international has been strongly linked with a move to Liverpool with the Reds having previously agreed a deal to sign the 26-year-old in the summer before the Lisbon club pulled out just before the transfer window closed.
Liverpool are still interested in the player but Queiroz insisted that United will not play a spoiling role.
'Manchester will not take part in speculation to promote individual or collective interests,' said Queiroz in an interview to Portuguese radio station Radio Renascenca.
'This is a film that has been repeated several times.
'The player (Simao) and Benfica deserve respect and that is why we will not enter speculations or make moves of private interest that have no respect for institutions.'
Benfica, who signed former Newcastle winger Laurent Robert yesterday, are keen to keep their club captain at least until the end of the season.
'There are no players to sell at Benfica,' said club president Luis Filipe Vieira.
'Benfica is a club that buys not sells.
'What we want is to go on the pitch knowing that we have a good team to win every game.'
Meanwhile, the agent for Monaco defender Patrice Evra, who has been linked with a possible move to United and Inter Milan, claims the French club are willing to let his client leave if they are happy with an offer.
Evra is currently ostracised from the Monaco squad after he admitted his desire to quit the Stade Louis II.
And Federico Pastorello believes a January transfer window switch to either Old Trafford or the San Siro is now on the cards for the 24-year-old French international after encouraging talks with Monaco.
'Things went well,' said Pastorello, 'and Monaco will not go against Patrice's departure.
'If an interesting offer is made to Monaco then the transfer will go through.'
United are believed to be Evra's preferred option as Inter would rather sign him now but not take him to Italy until June.
'Inter have worked directly with Monaco and myself and I told Manchester United about the situation,' added Pastorello.
'It is now up to the clubs to make their move. But it is true that Patrice really liked the way Manchester went about things. They were very professional with us.'