United are looking to bring in a new midfielder this summer as Paul Pogba's future continues to hang in the balance, with the Frenchman in the final year of his contract at Old Trafford.
Goretzka is one of the many players linked to the Red Devils, but the German reportedly wants to stay on at the Allianz Arena beyond 2022, and Nagelsmann, who recently took over as Bayern boss, is hopeful of keeping the midfielder at the club.
"I'm not involved enough that I have a say every day. I stay out of these issues," the 34-year-old said. "Of course I have talked to him about my plans for him. I've told him I'd be happy if he extended and I'm also confident.
"There are several topics involved when it comes to discussing a contract extension. I'll continue to focus on the sports side of things and show him he can be one of the most dangerous midfielders in Europe. He has potential to get even better."
Nagelsmann also revealed that Bayern might dip back into the transfer market after already snapping up Omar Richards, Sven Ulreich, and Dayot Upamecano. He added: "I said before that I'm taking over a well-functioning team.
"I haven't had the full team yet. On Monday we will be complete when others return, and then it's about finding the rhythm in training. I'm not worried about these scores. I think the first half today was good. We had control and played well, but we didn't manage to create a lot of chances in the final third. Our task as a club is to always observe the market. We have a good squad, but we can always improve it. Every coach in the world wants the best possible team."