The Premier League giants are hoping to improve their back-line as they seek to try for a top four finish.

Despite shipping out some of the deadwood, bringing in a new coach, and purchasing some of the world's biggest talents, Manchester United still appear not to have fully recovered from last season's disastrous campaign.

To make matters worse, Louis Van Gaal's tenure at Old Trafford has been hampered by injury after injury to key players, a worrying trend ahead of their upcoming match with Arsenal this weekend.

With the team struggling to find adequate defensive cover at the back, the Red Devils have been linked with moves for several players as early as January. Among them is former captain Nemanja Vidic, who departed in May on a free transfer to Inter but has struggled to adjust in Serie A.

While the 33-year-old could represent a short-term option due to his experience playing in the Premier League, reports indicate that the top target for Van Gaal is Borussia Dortmund's Mats Hummels. The 2014 World Cup winner has been long linked with a move away from Germany with the likes of Arsenal and Barcelona also being linked with interest in his services.

According to the Guardian, the club's executive board could be preparing to make a record-breaking offer of more than £32 million, with Manchester City having set that benchmark when they signed Porto's Eliaquim Mangala. The report also interestingly highlights Hummels' connection to Manchester United, citing an instance where the German star visited to view a match on his 18th birthday and also Van Gaal's term with Bayern Munich while the defender was a teenager in the youth setup.