Gernot Rohr says the team will work on their scoring problems ahead of their next 2019 Africa Cup of Nations match.
The Super Eagles have scored two goals in their three Group B matches.
Nigeria scored one apiece in their 1-0 wins over Burundi and Guinea, before their stuttering attack failed to make any impact in a surprise 2-0 loss to Madagascar.
That defeat saw Rohr's team drop to second place on the standings, giving them a much tougher last 16 tie - potentially against arch rivals Ghana - in Alexandria on Saturday evening.
"I know we have problems with scoring of goals, especially against teams who are well organised defensively," said Rohr.
"Madagascar didn't give us space to play, they defended together and our wingers were not able to break through.
"The performance was better in the second half, but it wasn't enough. We gifted the first goal and they became stronger, we have to work on our scoring problems and solve the problems before our next game."