Liverpool were held to a 0-0 draw by Everton at Goodison Park in an action-packed fixture.
Despite having opportunities, Nunez was unable to find the back of the net and was subbed off with 10 minutes remaining by Jurgen Klopp.
Speaking in his post-match press conference, the German manager was asked whether he had concerns over his big money signing.
Klopp said: "No. He had the start-stop integration, that's how it is. We play all the time, that means we cannot train constantly, he was suspended in a week when we had two or three normal-ish sessions, the rest were individual when he had to do a bit more.
"In the sessions when we had them he looked really good but he still has to be integrated, that's completely normal. So the way we played, it's not that we created… he had the chance where we passed the ball back and it was an open goal and Pickford was still there but I know that he will score in these moments in the future, that is clear.
"But it was super intense for him today, super. We had to make the decision; Bobby was injured before, now played two or three games really, really good. Wednesday-Saturday, traditionally difficult fixtures and that's why we decided to let Darwin start and he came through 80 minutes.
"No, it is not a concern or whatever, it is just the situation, it is all fine for the moment in that perspective.
Looking back at the game, Klopp added: "There are not a lot of derbies that will be in my book of games that I will watch back again in the future, one or two maybe but all the others not because it's never really outstanding football.
"It's a big fight, which everybody expects from both teams. We fought, we didn't play always extremely well but created enough, had top chances but didn't use them and then you cannot score. But how I said, if you can't win the derby, don't lose it."