LONDON - Manchester City coach Pep Guardiola insisted on Friday that he was "fine" despite admitting earlier in the week that his side's worst run of form since he took over as first team coach is causing him to eat less, lose sleep and suffer digestive problems.

Guardiola made his original comments in an interview with Amazon Prime Sport ahead of Wednesday's UEFA Champions League defeat to Juventus, which leaves City with a lot of work to do in order to even secure a place in the top-24 teams in the group.

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His side plays Manchester United in Sunday's derby, with just one win in its last 10 games and severe problems in defense.

Speaking to the press on Friday ahead of that game, Guardiola insisted he was "fine".

"In our jobs, we always want to do our best or the best as possible. When that doesn't happen, you are more uncomfortable than when the situation is going well," he admitted.

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"In good moments I am happier," he added, explaining that "when I get to the next game, I am still concerned about what I have to do".

"There is no human being that makes an activity and it doesn't matter how they do," he said.

Looking ahead to Sunday's game, Guardiola said his side had to "avoid making mistakes at both ends", and he commented that new Manchester United coach Ruben Amorim had already made improvements, despite losing two of his three league games in charge.

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"It's already there, you see all the patterns, the movements, the runners and the pace. He will do a good job at United, I'm pretty sure of that," he commented.