Manchester City boss Pep Guardiola admits he still feels responsible for their Champions League quarter-final exit last season.

His team suffered a shock defeat to Lyon in the quarter-finals in August and are preparing to start again at home to Porto tomorrow night.

City spurned a series of chances before a Moussa Dembele goal handed Lyon a surprise 2-1 victory in Portugal - with Guardiola's negative tactics and decision to start Eric Garcia criticised in the aftermath.

"It was a tough moment," Guardiola said of their exit in August. "I felt so responsible for how the club felt, all the players, I was not able to drive them and I still right now feel so responsible.

"But watching the games we have to accept the reality that we were not good enough. We did not play bad, we played some real good moments but we sometimes made mistakes and in this competition you cannot do it.

"The reality is, every player and manager, not just here, has to dream with high expectations. We did not perform at the level you have to perform to get through. We have to accept it with humility.

"When we accept this, it’s the best way to improve and to accept the new challenge. We will start from zero again knowing we have to improve."