Robert Lewandowski
Robert Lewandowski has already scored 30 goals for Borussia Dortmund this season. Reuters

The transfer window came and went without major incident for Manchester United as Sir Alex Ferguson followed through on his repeated claims that he would not make additions to his squad in January. A deal for Wilfried Zaha was completed, although the winger will remain at Crystal Palace until the end of the season.

It is in the summer when Ferguson likes to do his transfer business and there has been speculation of significant plans already afoot. Here are six players that could arrive ahead of next season.

Robert Lewandowski (Borussia Dortmund)
A move for the Poland international has been mooted since last summer and there have been increasing reports that a deal is set to go ahead in the close season. Lewandowski will have just over 12 months remaining on his contract come the end of the season and the 24-year-old has suggested that he would be keen for a move, putting Dortmund under pressure to sell.

Lewandowski has continued his prolific form, both in the Bundesliga and Champions League, this term, although it remains to be seen how he would fit into United’s already stacked front line.

Victor Wanyama (Celtic)
United have reportedly sent scouts to watch Wanyama in action on several occasions over recent months and it is easy to see why. The Kenyan has been a driving force in Celtic’s midfield since joining in the summer of 2011 and has been particularly impressive in their Champions League run this season.

Ferguson’s side has been crying out for a dynamic midfielder of Wanyama’s ilk for several seasons and it is almost becoming perverse that he hasn’t addressed the deficiency. Perhaps the summer will finally be the time and the 21-year-old could be the man Ferguson targets.

Marouane Fellaini (Everton)
If United opt against Wanyama then they could instead move for the all-round physicality and goal threat of Marouane Fellaini. The Belgium international could not have provided a more vivid display of his qualities to Ferguson than his dominant performances in the last two matches between Everton and United.

Everton will be reluctant to sell and would surely demand a fee in excess of £25 million, while competition for his signature is also likely to be provided by Chelsea.

Asmir Begovic (Stoke)
There have been strong reports of late that Ferguson is beginning to run out of patience with David de Gea and his inability to deal with the physical side of the Premier League. Begovic is one of several names to be linked as a possible replacement in the summer.

With Stoke having signed then loaned back goalkeeper Jack Butland on deadline day, it suggests that they may well be preparing for a summer exit for Begovic. The Bosnian has been an impressive performer, although it would be a brave move by Ferguson to opt for the 25-year-old over the still huge potential of De Gea.

Ezequiel Garay (Benfica)
With Rio Ferdinand’s contract still set to expire in the summer and Nemanja Vidic having been ravaged with injuries in the past 13 months, a new central defender may well be in Ferguson’s thinking. It has been reported that Argentina international Garay features prominently in his list of targets.

The 26-year-old has been an impressive performer for Benfica following a disappointing spell at Real Madrid, yet the Portuguese side’s financial situation could lead them to accepting an offer of around £15 million.

Kurt Zouma (Saint-Etienne)
Were United to go for a younger option in defense, they could instead swoop for 18-year-old Zouma. According to the Independent, United tried to sign the France Under-19 international last summer and have continued to monitor his progress since.

Rated as a future star for France, Zouma has been a regular with Saint-Etienne since late last season.