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 game against Crystal Palace, 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.