City have conceded just three goals in the last 12 games in all competitions, whilst also posing the best defensive record in the Premier League this season.
The 12-game run has also seen Guardiola's side go unbeaten since defeat to Tottenham Hotspur back in November.
The Catalan boss believes that whilst his defenders are all performing well, they must continue their impressive form into the second half of the season.
"Of course it’s important," he said at his pre-match media briefing.
"It's actions we should control, but I always had the feeling we concede few chances and concede few goals in previous seasons.
Guardiola also believes cutting out mistakes has immensely helped his defence in recent months.
"The mistakes against Leicester - we shouldn't do it - but we have improved on those terms.
"Those mistakes we have not done again and that's why we improve."