Nigeria coach Stephen Keshi has said that his side will have to improve if they are to make an impact at the World Cup in Brazil.
He was talking after they drew 0-0 with fellow World Cup finalists Greece in Philadelphia on Tuesday.
Both sides created chances but lacked a clinical edge to find the target.
"We will always have very difficult games but the motivation will be to do a lot better than we managed in our last couple of games." Keshi said.
"The truth is we didn't play our game. The importance of a friendly game is to know your weakness and what needs improvement.
"What I found out is that we were not able to keep the ball in our possession. The whole idea was to control the game."
Nigeria's best chances fell to Stoke City's Peter Odemwingie, Michael Babatunde (Volyn Lutsk), Ogenyi Onazi (Lazio) and Chelsea's Victor Moses late on but all of them failed to find the back of the net.
The Nigerians also drew 2-2 draw with Scotland last week and Keshi feels these games have given him and his players an insight into what lies ahead.
"All I need is the mentality and discipline to dominate the game and take chances," he added.
"In friendlies you can correct your mistakes but in a tournament it can cost us dearly.
"So we'll see how it goes in the next game because that is another chance to improve on this performance."
The next friendly for the African champions will come against the USA on Saturday in Jacksonville, Florida.
The team depart for Brazil on 8 June to prepare for their first match of the tournament against Iran in Curitiba eight days later.
They then play Bosnia-Hercegovina and finish their Group F campaign against Argentina as they attempt to reach the Last 16, as they did in 1994 and 1998.