Manchester City manager Pep Guardiola has said he is to blame for the team's Champions League struggles last season.
City will kick off their latest bid to win Europe's top club competition for the first time on Wednesday when Porto visit the Etihad Stadium.
The game comes two months after their surprise defeat to Lyon in last season's quarterfinals, making it the fourth consecutive year Guardiola's team have failed to make it past the last eight.
"I felt responsible for [the defeat to Lyon]," Guardiola told a news conference on Tuesday.
"How the club and players fought, I was not able to drive them. I feel responsible watching the game, we were not good enough.
"The reality is every team and manager has to dream with high expectations, but the reality is we have not performed to the level.
"I feel so bad for the players, but this is a new opportunity and we start again."
Guardiola has won every domestic honour since he arrived in England including two Premier League titles, but Manuel Pellegrini remains the only manager to take City into the semifinals of the Champions League after reaching the last four in 2016.
Since's Guardiola's appointment, City have often been among the favourites to lift the trophy, yet have seen their hopes dashed by Liverpool, Monaco, Tottenham and Lyon.
"I have the feeling that we are close," Guardiola said.
"Every season when I analyse the way we went out, I felt we are close, but in the same time we make mistakes that make you feel we don't deserve to go through.
"I don't think it's mental, it's about desire. Having won the domestic titles, the next is the Champions League, and we had a good opportunity.
"Now it's a new opportunity, and I think I believe. We talk about this, and we have to do things differently. "When you review the games -- Liverpool, Tottenham, Lyon -- always I had the feeling we are close, they were not better than us, none of them. They are little gaps but we have to solve it.
"When you don't go through, it's because you don't deserve it, and that's all."