Havertz is a top target for Chelsea, and the attacking midfielder is claimed to be pushing for the move to happen this summer.
But the two clubs are yet to find an agreement and Leverkusen are not prepared to let Havertz depart for less than they believe he is worth.
Ballack, who acknowledged that his young countryman has a lot of room to improve, is of the view that the 21-year-old should make the move, if he feels ready to take on the pressure of playing for a big club like Chelsea.
The ex- Chelsea star stressed that Havertz possesses the talents to make it at the top and believes the prospect of playing in the Champions League would also help the young midfielder develop.
Ballack told German outlet Sportbuzzer: “He has everything, but he is still in development.
“For such a player, it is also important to play in the Champions League.
“Therefore a transfer would be logical for him.
“But he will also know that the competition and expectations of a big club like Chelsea are greater than at Leverkusen.”
Ballack believes Havertz has the qualities needed to thrive in the Premier League, but will find the challenge to be tougher.
“Yes, whoever creates so many goals, scores goals and initiates decisive moments has an exceptional quality.
“The competition will be tougher than in Leverkusen, the pressure too – if he feels ready for it, then he should take this step.”
After spending £47m on Timo Werner this summer, it remains to be seen whether Chelsea will match Leverkusen’s high asking price for Havertz.
