Nigeria and Chelsea star John Mikel Obi's father has been abducted in Nigeria, according to his management.Michael Obi has not been seen or heard from since he failed to return home from work on Friday in Jos, the capital of central Nigerian Plateau state."John Mikel Obi's father was abducted in Nigeria on Friday," SEM Group said on Twitter.The player was told before Sunday's Premier League game between Chelsea and Stoke City, but decided to play.SEM said no ransom demand had yet been received and that Mikel had decided to play in the match "so as not to let down his team and family".His family told the BBC that they have had no contact with Obi senior but believe he is "safe and well".The Chelsea player's agent John Ola Shittu said that everybody in the family remains hopeful."It's been tough for the young man," Shittu said."The family in Jos reported him missing at the police station as expected but we're taking all necessary measures to find him.""We've told him to be brave and to stay calm."Shittu said the family has also not heard from anyone claiming to hold Obi senior.Kidnappings - more often of oil workers, the rich and famous - are a common occurrence in Nigeria.Footballers and their families are increasingly being targetted.In July 2008, the elder brother of Nigerian and Everton defender Joseph Yobo was seized in Port Harcourt, where kidnappings for ransom are most frequent.It was not clear if a ransom was paid but Nornu Yobo was released after being held for almost two weeks.