By Oluwashina Okeleji BBC Sport, Lagos

Enyeama says that the NFA has not been in touch with his club

The pair are among the three over-aged players called up by coach Samson Siasia for the Olympic football tournament, which begins on 6 August.

But barely two weeks before the start of the Games, both players have been told by their clubs that they will not be allowed to travel to China.

The Olympic football tournament is for under-23 teams, but three over-age players may also be fielded.

World football's governing body, Fifa, has confirmed to the BBC that clubs are not obliged to release over-age players for the Olympics, but they have asked clubs to comply with requests of national associations.

"The Fifa executive committee, during its meeting of 14 March, made an appeal to the solidarity of the clubs in order to release these players," a Fifa statement said.

Goalkeeper Enyeama, who plays for Hapoel Tel-Aviv in Israel, claims that the NFA have not contacted his club to seek his release.

I expected so much from the NFA but they have left me fighting this battle all by myself Ikechukwu Uche

"I have made frantic efforts for the club to release me for the Olympics but they told me to forget about it," Enyeama told BBC Sport.

"The club even went as far as saying that my country's FA has not been in touch with them or shown any strong desire to have me in the Olympic squad."

Uche says that his Spanish club Getafe only received an international invitation for the player last week and have since informed him to attend a pre-season training camp, instead of the Olympics.

"They claim there is no evidence to show that I am needed for the Olympics, and the fact that the invitation letter arrived late did not help matters," said Uche.

"I expected so much from the NFA but they have left me fighting this battle all by myself."

NFA spokesman Ademola Olajire says that they have written a letter to Fifa to have the players released for the Olympics.

"We are banking on Fifa to help us, we are not capable of doing anything about this situation if we don't hear from Fifa," said Olajire.

Meanwhile, defender Efe Ambrose has been cleared to play for Nigeria, after initial concerns over the condition of his heart, officials confirmed.