Nagelsmann's side face Atletico Madrid in their first-ever quarter-final but he feels that the tie being played over a single game could aid his side against the experienced Spanish outfit.
He said: "They have a lot of experience over two legs, but anything can happen in just one game.
"We will all be thrown into cold water, because of this situation."
The Bundesliga side will be without striker Timo Werner for the game after he completed his transfer to Chelsea and Nagelsmann wants other players to step up.
The 33-year-old manager said: "We don't have Werner and I won't say who will start.
"But we have players who didn't play when Werner was here who will now get their chance."
Atletico knocked out holders Liverpool to reach the last eight but coach Diego Simeone admits the result is meaningless as it took place prior to lockdown.
The Argentine manager: "A lot of months have passed, and all the excitement and turmoil that arose after the win over Liverpool has died down a bit because of the 100-plus days we've been in quarantine.
"Then with La Liga it all seems like far away now. That win will remain part of the history of Atletico Madrid. But now, a new journey begins.
"I'll repeat: tomorrow it's not important to win, it's the only thing that you can do. We'll prepare for the game in that way."