A frustrating campaign with injury had the best possible ending for Havertz, who won the Premier League title with Arsenal, ending their 22-year drought.
The German international only played 11 times in the top-flight as the Gunners were confirmed champions on Tuesday following Manchester City's draw against Bournemouth.
But the 26-year-old has shown glimpses of his best form in recent weeks, scoring the winning goal in Arsenal's 1-0 victory over Burnley, while netting in April's 2-1 defeat at the Etihad.
Following the euphoria of a league title win, Havertz's attention will quickly focus on the World Cup after their final games of the season against Crystal Palace on the Premier League final day and then PSG in the Champions League final, and Nagelsmann wants his forward to play a starring role.
“On the pitch, you are outstanding. Incredibly important for us. Stay healthy, clear your mind and go for it. You have everything we need to have a top goalscorer up front," Nagelsmann said.
Havertz is planned to start as Germany's No. 9 this summer and he should relish that weight of expectation on his shoulders.