Mikel is set to join up with his team mates on Friday
Fit-again Chelsea midfielder John Mikel Obi has joined the rest of his Nigeria team-mates on Friday.
Obi recently underwent knee surgery, raising doubts over his participation in this summer's World Cup finals.
The 23-year-old, who missed Chelsea's last four Premier League games and the FA Cup final win over Portsmouth, picked up the injury in April.
"He has completed his rehabilitation at Chelsea," a Nigerian Football Federation spokesman said.
Nigeria are training near Maldon in the English county of Essex and play a friendly against Colombia at Milton Keynes on Sunday.
The Super Eagles are due to face North Korea in Johannesburg on 6 June after playing Colombia in England on Sunday.
Goalkeeper Dele Ayenugba is the only other player yet to report to camp, following visa trouble. But Peterside has stressed that team officials are abreast with his situation, adding Ayenugba is expected to meet up with the squad in Austria.
Nigeria have been drawn in Group B in South Africa, with Argentina, Greece and South Korea. The open up their campaign against Argentina in Johannesburg on 12 June.