Barcelona have reportedly ended their interest in Borussia Dortmund's Mats Hummels - leaving Manchester United free to make a bid for the centre-back.

The Catalans are desperately looking for a couple of centre-backs this summer as Carlos Puyol has has hung up his boots while new manager Luis Enrique wants Javier Mascherano back in midfield.

Paris Saint Germain star Marquinhos and Valencia's Jeremy Mathieu are their two primary targets but following unsuccessful negotiations with both clubs, recent reports claim they are considering Hummels and Tottenham's Jan Vertonghen as alternatives.

However, now Spanish newspaper Sport claim the Catalan club are going no further with the signing of the German international and have earmarked Netherland star Daley Blind as a cheaper alternative should they fail to secure Marquinhos and Mathieu.

In this sense, Mathieu has publicly requested his club to negotiate with Barcelona, with the Catalans set to pay around £13m. Valencia is unwilling to listen offers below his £16m release clause.

"Valencia has an offer on the table from a very important club. I ask [Valencia] to understand the present situation and accept the offer. I have the opportunity to play at the biggest club in the world and it's the only one I want to play for at this moment, but I can't forget everything Valencia has given me and I want to leave in the best way possible," he said.

So with Barcelona looking somewhere else for defensive reinforcements, Van gaal is encouraged to step up the negotiations to secure Hummels.

The German international is said to be his top pritority to lead the defence next seaon and fulfil the huge gap left by the departures of Nemanja Vidic and Rio Ferdinand.

Furthermore, Dortmund completed this week the signing of the versatile Matthias Ginter – increasing the speculation about Hummels exit this summer.