City are 22 points behind current league leaders Liverpool and have all but conceded their Premier League title.
Bernardo told Sky Sports: "The Premier League has been a huge disappointment to be so far from Liverpool and now we have to fight for the second position
"It hurts a lot because when you start a season, you always want to go for the Premier League, it's the main competition and the most important for the fans. So it's very disappointing, no one expected us to be this far from Liverpool in January or February so it's something that we need to learn from. We need to understand what failed and how we can solve it.
"I don't think it's how you defend or attack, I think it's a mix of plenty of things. I think little details make a huge difference and if you look at us this season, all the little details never went out way. It's not an excuse, we should've done better, and we are very disappointed in ourselves."