Manchester City boss Pep Guardiola has questioned their mental toughness after defeat to Manchester United.

City blew a 2-0 half-time lead and the chance to clinch the Premier League title by losing 3-2 at home to local rivals Manchester United.

Guardiola's side trail Liverpool 3-0 at the halfway stage of their quarter-final tie and he admitted the collapse against United could play on their minds tomorrow.

“Yeah, it can happen," said Guardiola. “It's difficult in itself, it's difficult for our mood not winning and, yeah, that can happen.

“But maybe we will improve for the future on that, to realise that sometimes it's not enough what you've done to win the games.

“In the first-half we tried to do what we've done all season, but maybe it's not enough to win at Champions League level.

“If that's so, I will have to recognise that I'm not good enough or the way we want to play is not able to do that."