The Schalke 04 striker has confirmed that he is ready to win back his place in the Super Eagles squad ahead 2014 Fifa World Cup
The former Hoffenheim player’s last game for the Super Eagles came in a 0-0 friendly draw against Botswana in November 2011 - Stephen Keshi's first game in charge.
"I'd be lying if I said it wasn't frustrating at times, to watch your team play when you're not able to play. I was a bit dampened but I've learnt a lot from it and done a lot of work mentally and physically to get back to where I am now,” Obasi told BBC Sport.
"I've been working hard and waiting patiently for my chance, and when it hopefully comes I'm determined to make the best of it. As a professional you know the competition for places is really good and you want to be out playing.
"The coach has been very encouraging so I have to work as hard as I can to get back into the fold.
“It's heart-warming to hear the coach say that because it's more than two years since I last played for my country.
"But I cannot get carried away because without me they won the Nations Cup and qualified for the World Cup in Brazil.
"It's motivational to know that there is a chance to get back but I must work extremely hard to earn a recall.
"I can't kid myself thinking it's going to be easy. But the hard work obviously starts now," he concluded.
Obasi and Haruna Lukman are the only Nigerians to have appeared in Fifa World Cups at all levels [Under 17, Under 20 and Senior].