The Super Eagles kept a clean sheet against Libya but Gernot Rohr insists that there are still concerns about the defence.
The defence led by Udinese's Wlliam Troost-Ekong and Brighton and Hove Albion's Leon Balogun prevented the Libyans from scoring a single goal but Rohr is still concerned.
During the cause of the game Ola Aina had to come in for Shehu Abdullahi who could no longer continue while Jamilu Collins joined the attack as often as he could.
The German tactician watched on as an Odion Ighalo hat-trick with a Samuel Kalu screamer gave the Super Eagles four goals and maximum points from the encounter to seal their second win in group E of the AFCON qualifiers.
The result reflects the Super Eagles dominance over the course of the game, but things were not so easy during the first half as the Libyans threatened to score with Nigeria holding just a one goal lead.
Speaking in his post match conference Rohr revealed that his team can do so much better in terms of organisation in defence.
He said, "This result does not mean we had a perfect game today. We had problems defensively especially in the 1st half and before we play Libya again in 3 days, we must improve on our weak areas."
What the result however does is give the Super Eagles three points which sees them second in the group after South Africa beat Seychelles 6-0 to remain top.
The Super Eagles continue their campaign when they travel to Sfax Tunisia for the return leg against Libya scheduled for Tuesday, October 16.