Martin Jol believes Tottenham's summer spending has strengthened the North Londoners' long-term future.
The Dutch tactician knows Bale will be a great signing, but feels Kaboul is already playing like a seasoned professional.
Jol believes the French defender has proved his class and is not worried about the former Auxerre man getting carried away with success.
"I feel we have invested wisely in good young players for the future," stated Jol.
"Gareth Bale is very young and Younes Kaboul is playing like a 25-year-old but he is only 21.
"Kaboul has proved to me he is a quality player and it is certainly a wake-up call for him because he proved he can play well at the back and it doesn't mean anything.
"We have got to prepare him. We've warned him what to expect and until now he is doing well.
"He is strong, quick and good in the air. He is a very good asset and I feel there will be no problem with him."