Chelsea legend Michael Ballack excelled as a young player for Bayer Leverkusen, before making a move to German giants Bayern Munich.

Ballack is rated as one of Germany’s greatest ever midfielder, as the German legend held legendary status for Bayern Munich and Chelsea, despite having spent only four years with each club. Ballack will eventually retire at Bayer Leverkusen.

Meanwhile, former Bayer Leverkusen’s CEO, Reiner Calmund, believes Kai Havertz is an even greater talent than Ballack.

He told Goal: “At Leverkusen we had three absolutely exceptional midfielders in Michael Ballack, Emerson and Bernd Schuster, whose careers I have followed intensively from the start.

“Ballack was the most dangerous, Emerson shone with his versatility and Schuster was great from a strategic point of view. If you compare these guys to Havertz when they were 21 years old, Kai is superior to all three.

“Voller also shares this view that none of the three at this age had such skill. He explained to me that Havertz would also be the more exceptional player in the medium term.”