Nigeria coach Shaibu Amodu has told Newcastle United striker Obafemi Martins to get serious about his career.
He said: "Martins needs a look at his psyche. I am worried about him.
"Obviously he's a good player but he needs to be prepared mentally to take up the challenges.
"His team have found themselves in a precarious situation and I think psychologically now he should be worried himself.
"I haven't had the opportunity to work with Martins closely because since I came back to the national team he has not been able to show up.
"His excuses have been injury but I think he is injury-prone. He needs to work more on his fitness.
"He's small in physique and plays in attack so he is prone to knocks.
"The only way you can keep playing at that level is to be very, very fit and to stay away from all the social vices.
"I'm not saying that is what's involved but it is a clear criteria if you want to stay at the top of your game all the time."