Tottenham's International Technical Coordinator Steffen Freund believes Gareth Bale has justified the €100m fee paid for him by Real Madrid since his arrival in the Spanish capital.
The Wales international left Spurs in the summer of 2013 for Santiago Bernabeu and played a key role in the club winning the Copa del Rey and the Champions League in his first season at the club.
And though some supporters have recently turned on the former Southampton youngster, Freund told Goal that the winger has already paid back much of the hefty fee Real spent on bringing him to the club.
"Let me answer that as a CEO: with his transfer, Real Madrid wins two titles. In the Champions League final he scored the decisive goal for 2-1 and in the Copa del Rey against Barcelona he made the difference," he said.
"This brings lots of money and his shirt sells easily. I would say he is worth the money.
"To Tottenham he was a big loss. World-class players like him can't be replaced over a long period."
Freund worked closely with the 25-year-old during his time at White Hart Lane and has always been impressed by the drive to succeed Bale has shown in his career.
And he was quick to defend the Welshman for his style of play after he came under fire for a perceived selfishness when on the ball.
"He is exceptional," Freund added. "Even at a young age he had an incredible drive for the goal and was unstoppable. His physical skills are unbelievable and he keeps working on them. His dynamic is scary. Plus, he knows how to benefit from his technical strength.
"The most impressive thing to me is his free-kicks with the left foot. He must be the first football player who can shoot in four directions at the same time. I remember a goal against Liverpool in 2012. The ball flew so strangely and Pepe Reina stood in the wrong side of the goal. Everybody thought it was deflected, but it wasn't.
"People in Germany would call him an individualist. This is not unusual for stars like him. He is introverted and not one who gets in front of the team to hold a speech.
"He leads with actions. If nobody wants the ball, he goes and takes it so his colleagues can breathe. His quality is phenomenal."
At Tottenham, Freund has worked as part of a coaching staff alongside a technical director, with Franco Baldini the current incumbent in north London.
And the former Leicester City midfielder believes more Premier League clubs will follow the same structure in years to come, though he did praise Arsene Wenger for "handling both duties" at Arsenal.
"People in England are starting to rethink this. Arsene Wenger is doing a sensational job at Arsenal for 17 years, he handles both duties.
"Other people are completely overwhelmed by it. That's why the role of a director becomes more important. The boards realise that a football club is not a factory where one person decides everything."
The 45-year-old has been on the staff at Spurs since 2012, but he admits he is likely to leave the club this summer, though he revealed he could remain in the English game.
"My tendency goes to taking a new challenge in the summer. Whether in England or in Germany is completely open.
"There have been some interesting talks. To me the perspective is the most important thing, may it be as a sporting director or a coach."
Freund spoke to Goal while taking part in the Snow Football World Cup in Arosa.