(CNN) -- Chelsea midfielder John Obi Mikel has made an emotional appeal after his father was abducted in his native Nigeria.

"Please just let him go," he told Sky Sports News.

"He's just an old man, he hasn't done any harm to anyone as far as I know and I don't know why he has been taken."

Michael Obi, who runs a transport company in Jos, the main city in Plateau State in central Nigeria, has not been seen or heard of since he failed to return home from work last Friday.

Obi Mikel was told of the problem just before the start of Chelsea's Premier League match at Stoke Sunday which finished goalless and said his father was at the forefront of his thoughts throughout the match.

"Nigeria is the country I am from, I've always tried to help my country in any way I can, playing for my country or anything," he said.

"This is a time where I need the country to help me. Whoever has got my dad, whoever knows where my dad is, please contact me and hopefully he can be released."

Chelsea have given Mikel their support in a statement on their official website.

"Everyone at Chelsea Football Club was very concerned to hear that John Mikel Obi's father has been reported as missing and possibly abducted.

"We will give Mikel and his family our full support at this most difficult time."

Mikel confirmed they had not heard from his father's abductors and no ransom had yet been demanded.

Answer the following questions:
1. who play for Chelsea?
2. did something happen to one of his family members?
3. which one?
4. what is his name?
5. what happened to him?
6. in what country?
7. what position does the son play?
8. when did he learn about the incident?
9. for what league?
10. on what day?
11. where?
12. is his team supportive?
13. how do you know?
14. where is the son from?
15. do they know what the kidnappers want?
1. John Obi Mikel
2. Yes
3. his father
4. Michael Obi
5. he was abducted
6. Nigeria
7. midfielder
8. before a football match
9. the Premier League
10. on Sunday
11. at Stoke
12. yes
13. from a statement on their official website
14. Jos
15. no