Pep Guardiola has insisted that Manchester City need to be at their best against Schalke and has asked his players to learn from Paris Saint-Germain and Real Madrid's premature exits from the Champions League. 

The reigning Premier League champions had to dig deep to register a comeback 3-2 win at Schalke in the first leg of their Champions League last-16 tie.

However, despite being the outright favourites, Real Madrid and Paris Saint-Germain's astonishing last-16 exits have made the Manchester City boss extra cautious. 

The City manager said: "We have a tendency - myself as well - that when we see the draw we always say who is going to win. After the first leg, everybody 'knows' who is going to win the second one," as quoted by ​Daily Mail

"But a week ago we didn't expect PSG would happen, or Real Madrid. Every game is completely different but for people who say there is nothing to do - one sent off, one red card, one goal in the first minute, many things can happen in 90 minutes in this kind of competition."

"I am sitting here thinking we still have work to do, that's my feeling today."

City are one of the favourites for the tournament this season, but Guardiola has insisted time and again that still isn't convinced of his team's pedigree in Europe. They still are alive and kicking in all four tournaments this season and are determined to finish as strongly as possible.