JOHANNESBURG (Reuters) - Everton striker Victor Anichebe is expected to finally commit his international future to Nigeria with a debut for the under-23 team in their final Olympic qualifier against South Africa in Abuja on Wednesday.

Nigeria will qualify for the men's tournament at the Beijing Games in August if they beat the visitors, but failure to win will allow Ghana, who have already completed their campaign, to advance instead.

The 18-year-old Anichebe, who is also eligible to represent England, is expected to be included in the starting line-up for what will be his first formal appearance for Nigeria.

However, doubts remain over Chelsea midfielder John Obi Mikel, who had been called up for the tie but was not expected to arrive in Abuja before Tuesday, officials said.

Nigeria coach Samson Siasia had previously warned he would not use players who arrived belatedly for call-ups.

Obi Mikel featured as a late substitute for Chelsea in their 2-1 win over Arsenal in the English Premier League on Sunday.

Nigeria, who won the gold medal at the Atlanta Games in 1996, are chasing the last of three places available for Africa in the 16-team tournament.

Cameroon and the Ivory Coast have already qualified.

(Editing by John O'Brien)