Pep Guardiola admitted on Tuesday that he still feels responsible for Manchester City's Champions League exit last season, saying they have to close these gaps as they chase European glory. City, who host Porto in their opening group match tonight, have never gone beyond the semi-finals of the competition. Memories of the quarter-final loss to Lyon in August remain fresh for Guardiola, who won the competition for the second time as Barcelona boss in 2011 but has failed to lift the trophy since.

"It was a tough moment," Guardiola said. "I felt so responsible for how the club felt, the players. I was not able to drive the club and I feel 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."