Manchester City manager Pep Guardiola has again cast doubt on the Premier League champions' readiness to win the Champions League for the first time despite being favourites for the competition.
City host Bundesliga strugglers Schalke on Tuesday with a 3-2 first leg lead in their last 16 tie hoping to avoid the pitfalls that did for Paris Saint-Germain and Real Madrid in Champions League shocks last week.
Guardiola admitted even he was taken aback by Manchester United's stunning 3-1 win in Paris and holders Madrid's capitulation to a talented young Ajax team, but refuted suggestions their elimination had cleared the way for City to finally conquer Europe.
"We are teenagers in this competition that's my feeling. It's not excuses, of course we want to win it," said the Catalan coach on Monday.
"You have to dream and point as high as possible but in the same time you have to accept there are other teams thinking the same with a lot of quality and lot of talent."
Guardiola was annoyed by City's mistakes in conceding two penalties and having Nicolas Otamendi sent off 22 minutes from time in Gelsenkirchen three weeks ago despite turning around a 2-1 deficit with 10 men through late goals from Leroy Sane and Raheem Sterling.
And he used that experience to warn his players against any complacency.
"In domestic competition there is another game, in this competition there is not another game. It is something unique, the focus is incredible and when you make something wrong they (the opponent) punish it," he added.
"Schalke had two shots on target and scored two goals. We played 23 minutes 10 v 11 when we could avoid that second yellow card from Nico.
"We are lucky today we are here 3-2 up when we could be 3-1 or 4-1 down. That's the reality in this competition. (There is) work to do, be calm and focused."
Along with the suspended Otamendi, Fernandinho will again miss out through injury, but the Brazilian's absence has not been felt as badly as first feared due to Ilkay Gundogan's form.
The German has deputised ably in the holding midfield role.
Tedesco hanging on Schalke travel to Manchester City for last 16 second leg with head coach Domenico Tedesco barely hanging onto his job and confidence at rock bottom.
Schalke's fortunes have nose-dived since first leg defeat after leading at break, leaking 11 goals in three heavy defeats to leave them four points from the Bundesliga relegation places.
Tedesco, 33, has been told he has two games to prove himself.
Schalke's new sporting director Jochen Schneider says only good performances at City and home to third-placed RB Leipzig next Saturday can save Tedesco.
Man City have won their last nine games at the Etihad Stadium, but the Schalke squad are hoping for an unlikely away victory and want Tedesco to stay on.
"Of course we do — no one has ever said anything different," said striker Guido Burgstaller.
Morale in the Schalke squad is so low after Friday's defeat that all the talk was on avoiding relegation, with the prospect of facing the Premier League leaders in their own backyard barely registering.
"This is not a pleasure trip," says Schneider.
"The anticipation is overshadowed by the situation in the Bundesliga."
To compound their problems, Schalke's playmaker Daniel Caligiuri misses the trip to Manchester, sidelined for the next four weeks by a leg injury.
Likewise, striker Mark Uth and midfielder Amine Harit, who were dropped for the defeat at Bremen, have also been left out of the squad for Manchester for disciplinary reasons, but full-back Hamza Mendyl has been added.
It's all a far cry from last season when the Royal Blues finished second in the Bundesliga to qualify for the Champions League in Tedesco's first season.
Despite qualifying for the knockout stages in Europe, they have been no higher than 11th in the Bundesliga this campaign
