Mats Hummels
Hummels has had a lot of problems with injuries this seasonReuters

Manchester United have reportedly made an opening bid of £21.5 million for Borussia Dortmund defender Mats Hummels.

United were heavily linked with a move for the German in both the summer and well as the winter transfer windows this season, but a move failed to materialise as Dortmund refused to sell their captain.

However, now with Dortmund Jurgen Klopp set to leave the Westfalenstadion and the club not being able to qualify for the Champions League, Hummels is expected to leave the Bundesliga this summer, with the German international himself admitting that he is interested in playing abroad in the future.

"I think moving abroad would be good for my professional and personal well-being," the defender had earlier told German publication. "Eventually, I'd like to leave the Bundesliga."

And Manchester United, taking advantage of this opportunity have reportedly made an initial offer of £21.5 million for Hummels, according to German newspaper Bild.

Although Dortmund value the centre-back around £35 million, United are reportedly confident that they can land him for much less due to him not being in the best of forms this season.

However, the Bundesliga side may be sticking to their original asking price of £35 million considering Hummels still has two more years remaining on his current contract and he is under the radar of a number of top clubs.

Meanwhile, former Manchester United player and assistant manager Phil Neville has backed Marouane Fellaini to shine during Manchester United's Premier League clash at Everton on Sunday.

The Belgian was an unused substitute during Red Devils' Premier League clash at Everton in 2013/14, but this time he is most likely to start, having managed to establish himself as one of the key players under van Gaal this season.

And Neville, who has played for both United as well as Everton, is confident that Fellaini will do well on his return to his former club.

"I think it'll be good for Fellaini to go back to Goodison now because he's going back in a better of state of mind," the defender told United's official website. "He's in better form and I think he's going there full of confidence."

While many expect the Belgian to be booed by the Everton fans on his return to Goodison Park on Sunday, Neville insists that the Toffees fans will still have respect for him.

"What happened in terms of his departure from Everton has been forgotten about now so Everton fans can probably look at it and say Marouane did a great job for us."