Manchester United and Liverpool target Mats Hummels has revealed he is losing sleep at Borussia Dortmund because he is agonising over his future.
Bayern Munich and Barcelona have also looked at Hummels and the Germany centre-half admits the speculation is taking its toll on him.
Hummels, whose Dortmund contract expires in June 2017, is torn between leaving and staying and told Sky Germany: "It's a very difficult decision, and when I finally make it people will understand how hard it is for me.
"It's been taking me at least half an hour extra to fall asleep for several weeks now because this is such a big issue for me."
His father and agent, Hermann Hummels, claims the defender could return to Bayern where he spent the early part of his career.
"Mats is facing an enormously important decision in his career, in his life," said Hermann Hummels.
"Dortmund are back among Europe's best clubs and that is making the decision even harder for him.
"If he were to leave Dortmund, then he could only go to five or six top clubs, and of course Bayern are one of them."
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