Guardiola, who has one more full season remaining on his present contract, insists that is not the case.
Guardiola remains wary of facing Jose Mourinho's United side on April 7, and says his team will turn into "spectators" after training on Saturday morning as they wait to face Stoke on Monday.
"My agent is not in town".
City are keen to secure the services of Guardiola for the long term and talks had been planned for the summer.
A 4-0 win in Switzerland in the first leg three weeks ago made qualification nearly a formality for a team that is 16 points clear in the Premier League and one of the favourites to win the Champions League. "But what happens in the quarterfinals, depends on our level in the Premier League".
Guardiola acknowledges that they are closing in on glory but stresses the job is not completed yet. "The distance [we are ahead] is not normal in the beginning of March; it's nearly done but we are not the champions", he said.
Speaking on Tuesday, Guardiola said: "I accept the decision because I have to do but that doesn't mean I agree or not, or they are right or not".
"We did an nearly immaculate group stage, knocking out one of the best teams in the world in Napoli and Shakhtar and we had a very good first leg and a good first half tonight".
And it was something to savour for Basel, the Swiss champion that has been a scourge of English powers with wins over Manchester United, Chelsea, Liverpool and Tottenham in European competition since 2011.
"We know we have to give good performance to compete in those situations but we will try to be ready for that".
"We have a certain pride", Basel coach Raphael Wicky said, "and against a team that plays every three days and is beating everyone, it's very special".
'Nobody thought we were going to lose against Basle.
"You have to be focused because Stoke away is always complicated".
Stoke are now second-bottom in the Premier League, and Guardiola believes facing a team battling for survival after a full weekend of fixtures could make it a more hard test for City. City thrashed the Potters 7-2 when they met earlier in the campaign but Guardiola is not thrilled about the prospect of a trip to the bet365 Stadium on a Monday night.
He was not happy with the display, though, saying his players "forgot to attack" and is hoping for better when they travel to relegation-threatened Stoke on Monday.