Coach Samson Siasia admits Nigeria's dropped points in Ethiopia stemmed from last week's friendly with Argentina.
The 2012 Nations Cup qualifier ended 2-2 in Addis Adaba, leaving the Super Eagles three points behind Group B leaders Guinea with two matches left.
Having beaten Argentina 4-1 in Abuja last Wednesday, the Nigerians arrived in Ethiopia only hours before kick-off.
"The boys probably took Argentina more seriously and approached Ethiopia with a relaxed attitude," said Siasia.
"This cost us dearly. Admittedly, there were the problems of fatigue, high altitude and other minor things - but we didn't play well."
The Super Eagles are set to play Argentina once again, in another friendly in Bangladesh on 6 September, but the coach insists that qualifying for 2012 Nations Cup is his main objective.
"We paid the price in Ethiopia but we cannot make the same mistake twice, so attention is firmly on a Nations Cup ticket," the former international told BBC Sport.
Nigeria face Madagascar on 4 September in a crucial Nations Cup qualifier, before travelling to the Bangladeshi capital Dhaka to take on the Argentines just 48 hours later.
With the trip to Antananarivo a priority, Siasia says he plans to ring the changes in his squad in order to find the right mentality.
"We plan to travel to Madagascar with players who have the right attitude and mindset towards what is at stake," Siasia said.
"However, we feel the time is right to ring changes in the team and we are going to give opportunities to others too.
"There will be changes to playing personnel, the attitude and mentality will be different and fresh legs will be brought in."
On 1 June, Argentina fielded an experimental side - with Lionel Messi, Carlos Tevez, Javier Mascherano and Sergio Aguero all absent.
The Nigeria Football Federation (NFF) says its latest contract ensures the South Americans will take a full-strength squad to Dhaka.
"I'm not bothered about Argentina, we can beat them 4-1 again with Messi and others but it counts for nothing if we fail to qualify for the Nations Cup," Siasia insists.
Meanwhile, reports in the local media claim that Siasia and the Nigeria Football Federation (NFF) are expected to hold crisis talks to discuss qualification for next year's African Cup of Nations.
The football authority will meet Siasia this week in a bid to thrash out challenges facing the team, according to the NFF's general secretary Musa Amadu.
If the Super Eagles win their next two Nations Cup qualifiers - in Madagascar in September, and at home against Guinea a month later - they will automatically qualify for next January's finals.