City go into Wednesday evening’s second leg 3-1 ahead on aggregate, but the boss insists the job is only half done.
He also says that football can throw up many surprises, so his players have to be ready and mentally prepared for the task ahead, despite the two-goal advantage.
“In football everything can happen, and we have to be aware of that,” said Pep.
“We have respect for Copenhagen and how they play. The Champions League is Champions League. The best eight teams in Europe [will move to the next round].
“We have the chance to be in quarter-finals again and this is the target. We’re not far off that.
“The way Copenhagen defend - they are compact – and all the movements they do really well.
“I am always aware of the opponents, but I especially look at our players.
“We struggled there last season; Bayern Munich were not able to win in Copenhagen.
“They play two years in a row with the same manager, and they have a strong striker. They are compact and do really good movements.
“My concern is always there. Otherwise I would not be here, but I prefer to start 3-1 up rather than 0-1 down.
“I would like us to be ahead 7-0, but that normally doesn’t happen in the Champions League. I want us to perform the way we have to do.
“Red cards or bad decisions can happen in football. If we conceded another goal in the group stages, we are second in the table and the draw would have been Real Madrid not Copenhagen.
“In football the details make the difference. Prepare well, mentally and read what they have to do.
“Respect Copenhagen, because this competition deserves it.”
Guardiola says he won’t know his line-up until Wednesday morning as he assesses how his players have recovered from the 3-1 win over Manchester United.
One player who won’t feature is Jack Grealish, who remains sidelined with a muscle injury.
“Selection all depends on how people recover from the last game,” said the boss.
“That’s all. We will take a selection tomorrow morning. It’s really important to be focused.
“Jack is not ready. I don’t know [when he will be available].
“The competition is getting better, tougher. Always I have the feeling to arrive in the semi-finals is harder.
“Teams are better, managers are better. More difficult now than when I was a player.
“I would not undermine what we achieved at Barcelona, that was really good.
“Every moment is every moment. Every game was difficult. Every step you do is complicated.
“You have to be good in the right moment, mentally, physically. I give the same credit for the one we won and the two at Barcelona as well.”
