The reigning champions of England and Spain face off at the Etihad Stadium on Wednesday (AEST) in the first leg of their Champions League quarter-final tie.

While Atleti has become famed for its organised and somewhat defensive set-ups, City is considered one of the finest footballing sides anywhere in world football.

However, ahead of facing Simeone for a fourth time in their managerial careers, Guardiola defended the Argentine's style of play.

"I'm not going to talk one second about this stupid debate," Guardiola said at the pre-match news conference.  "Everyone tries to win the game. If they win they are right, if we win we are right. It's for the players, the difference will be there. Honestly, not one second.

"After watching Atletico there is a misconception, wrong, about the way Simeone plays. It's more offensive than people believe. 

"He doesn't want to take a risk in the build up but they have quality in the final third. They know exactly how to play. In the moments of the game, these situations are really good."

Guardiola, who has won two of those previous three meetings with Simeone, added: "What is playing ugly? 

"My team won 1-0 at Old Trafford and Bernardo Silva spent five minutes in the corner, that is not ugly. It's defending the position. 

"I'm here to talk about what we try to do. I never judge the opponents. What they do, what we have to do to win."

City has won eight major domestic honours in Guardiola's five full campaigns at the club, but it has yet to lift the Champions League under the Catalan coach.

Guardiola has at times been criticised for overthinking his team selections and he joked he will take a different approach in the first leg against Atletico.

"In the Champions League I always overthink," he said. "There are always new tactics. Tomorrow you will see a new one. I overthink a lot, that's why I have very good results.

"It would be boring if I always played the same way. If people think I play the same against Atletico and Liverpool, I don't like. 

"The movements are different, the players are all different with different personalities. That's why I overthink and create stupid tactics.

"Tonight I take an inspiration and I'm going to do incredible tactics tomorrow. We play with 12 tomorrow!"

While Guardiola and Simeone have crossed paths before, Wednesday's (AEST) match will be the first time City and Atletic have faced off in European competition.

Guardiola has won three of his four meetings with Spanish clubs in the Champions League while in charge of City, with those being the most recent three.

City's reward should it better Atleti over the two legs will be a semi-final against either Real Madrid or Chelsea, the latter a possible repeat of last season's final.

The Citizens are also in the semi-finals of the FA Cup and lead Liverpool by one point at the top of the Premier League ahead of the two sides facing off next Monday (AEST).

That game could go a long way to determining which team wins the title, but Guardiola is only focused on the Atleti match for now.

"If you don't play these games you're out of the competition," he said. "It's a joy to be here every season. To arrive every season, April, May to fight for titles we've done well. 

"But any bad results now and you're out of competitions. Every opponent is tough in this stage. Every team has a particular way to play. You have to adapt and adjust."