The European Cup winner announced last week that he would not extend his stay at the Citizens but weekend speculation suggested he could be convinced to stay if he leads the side into Europe.
But Keegan, who made his name after leaving the Old Showground to join Anfield giants Liverpool, insists that is not the case.
He said: "I will not be staying beyond my contract. People who really know me know that is what I will do.
"Whatever we do next season will not make any difference."
Last week, City keeper David James urged the club to clarify the situation.
He said: "The gaffer is doing a good job, and that's showing in the performances.
"But it would be nice to know that something is going to happen and when it's going to happen."
Keegan will play in a Tsumani benefit match on March 27, as a team of former Liverpool stars take on a celebrity XI at Anfield.
Kenny Dalglish, Bruce Grobbelaar, John Barnes, Ian Rush and Alan Hansen will all pull on the famous red shirts once more.