Borussia Dortmund manager, Jurgen Klopp, says he gets tears in his eyes when he watches Shinji Kagawa at Manchester United.
Dortmund have sold their best players for three seasons in a row, with Nuri Sahin, then Kagawa and soon Mario Gotze all leaving the club for ‘greener pastures’.
Despite trying to convince Gotze not to go, Klopp was ultimately powerless to stop the talented young midfielder from activating his buyout clause, when Bayern Munich gave him an ultimatum.
Kagawa, meanwhile, may have been crowned Premier League champion after his first season at United following his move from Signal Iduna Park, but Klopp has not exactly celebrated with the Japanese playmaker.
In a wide-ranging interview with the Guardian’s Donald McRae, Klopp says that he thinks Kagawa is criminally under-utilised and played out of position at United.
He also says that if the players who have left Dortmund had only been a little more patient, they could have helped him develop a team of world beaters.
"Shinji Kagawa is one of the best players in the world and he now plays 20 minutes at Manchester United - on the left wing!” Klopp told the Guardian.
"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.
"One year before that Nuri Sahin went because Real Madrid is the biggest club in the world. If players are patient enough we can develop the team into one of the biggest in the world."
Klopp will marshal his troops one last time for the season against Bayern Munich in the Champions League final on Saturday night.
No matter what happens, the way he has turned his team into a European powerhouse in the few seasons since joining from minnows has put Klopp firmly on the football map.
And most neutrals will be gunning for Dortmund at the weekend, thanks to the swashbuckling, good-natured, honest and open way Klopp has gone about his business, even in the face of losing his best players time and time again.