The Foxes have endured a torrid season thus far, particularly since the turn of the year as they have lost five and drawn one of their Premier League games.
Leicester are still awaiting their first league goal of 2017 and are now just one point above the dropzone, but Ranieri believes that things could get even worse when his side head to The Den to face League One opponents Millwall on Saturday.
"They have beaten two Premier League teams," he told reporters. "We know this. We are the underdogs if they beat Bournemouth and Watford, who are above us in the league.
"Millwall are a good team - compact and full of confidence. They play well together but we are ready. We have to play for our fans. There will be 3,000 of them there with us to support us and I want to see our players fight.
"My mind doesn't change if I win or if I lose. I stay positive to try to help my players. You have to continue to believe. We are working so hard. When you work hard, when you believe in something, at the end you achieve something."
Ranieri, who also revealed that Islam Slimani and Leonardo Ulloa will not be fit in time to feature in South London, is now the bookies' favourite to become the next Premier League manager to be sacked.