The 21-year-old has been in impressive form for his German club during the 2019-20 campaign, scoring 16 times and providing nine assists in 42 appearances in all competitions.
However, Bosz has revealed that he expects to count on the attacker during the 2020-21 season.
"I don't feel that he is thinking too much about transferring. Neither are we," Bosz told reporters. "I certainly don't have the impression that this will be his last game for the club. He is still under contract with us and I have to assume that he will be with us next season too.
"That will include the German Cup final next month (July 4, vs. Bayern) and the next Europa League game against Rangers in August. Of course, that's all dependent on nothing happening before then."
Havertz's current deal at BayArena is due to run until June 2022.