Borussia Dortmund defender Mats Hummels rejects offer to join Manchester United in the summer

Manchester United's primary defender target Mats Hummels has reportedly turned down a chance to move to Old Trafford in the summer and will remain with Borussia Dortmund, with whom he has a contract until 2017.

The Germany international, who was Louis van Gaal's number one choice to strengthen his back line, has decided to remain with the Bundesliga club beyond the current campaign.

The German side were unsure of Hummels' future plans and had admitted that he could be sold in the summer if interested club's meet their demands regarding the fee. The defender was valued at around £35m ($54.8) by his current employers.

But according to sporting director Michael Zorc, Hummels has performed a U-turn and decided to stay with them despite the club having a poor domestic campaign. Dortmund are also without a manager after the departure of Jurgen Klopp in April, but have confirmed the appointment of Thomas Tuchel as his replacement for the upcoming season.

"It made sense that Mats was thinking about his future, but I always pointed out that we plan [for the future] with him," Zorc said, as quoted by the Daily Mail.

Van Gaal is desperate to strengthen his defence in the summer and has targeted various players like Athletic Bilbao's Aymeric Laporte and Atletico Madrid's Joao Miranda, but his priority was the German World Cup winner, who had earlier hinted that he could move abroad to further his development as a footballer.

However, following the rejection their primary defender target, United have not wasted any time in finding an alternative, with reports suggesting that the Red Devils have already agreed a pre-contract with Valencia defender Nicolas Otamendi, who was a target for the Dutchman even during the January transfer window.