Borussia Dortmund coach Jurgen Klopp admit he's disappointed seeing Shinji Kagawa play a bit-part role at Manchester United.

Klopp says his former BVB star is wasting his talent.

Klopp told the Guardian: "Shinji Kagawa is one of the best players in the world and he now plays 20 minutes at Manchester United - on the left wing!

"My heart breaks. Really, I have tears in my eyes.

"Central midfield is Shinji's best role. He's an offensive midfielder with one of the best noses for goal I ever saw.

"But for most Japanese people it means more to play for Man United than Dortmund. We cried for 20 minutes, in each others' arms, when he left."