Mikel Obi is being closely monitored by Chelsea in Nigeria's camp ahead of the Nations Cup in South Africa.
Mikel joined the Faro, Portugal camp on Sunday alongside fellow Blue Victor Moses but the player is under the supervision of his agent John Ola Shittu.
Shittu's presence is believed to be in the interest of Chelsea, his club have kept the midfielder out of action for a few weeks following the knock that forced him to be substituted in a Premier League clash with Norwich on Boxing Day, reports futaa.com.
Mikel is feared to be nursing an injury due to his recent omissions from Chelsea games but the defender declared himself fit on arrival in Portugal
The former Lyn Oslo ace only signed a five-year contract extension with the Blues and with very few option in the defensive midfield, the Londoners see Mikel as a valued asset hence the decision to keep a close surveillance on him through his agent.