Leicester will look to build on their recent improved form when they host Premier League leaders Chelsea at the King Power Stadium on Saturday.
The hosts have struggled in the defence of their Premier League crown and come into this game in 15th place with just 21 points from their opening 20 games.
They are, however, unbeaten in their last three ties, having defeated West Ham 1-0, held Middlesbrough to a 0-0 draw, ahead of securing a hard-fought 2-1 win over the Toffees in FA Cup action.
Ahead of this clash, Ranieri said that Leicester will face a tricky test against a wounded Chelsea side.
He told the club's official website: "They started not so well but after a few matches, [Antonio] Conte understood the team and the players,” Ranieri said. “They’ve made a very good part of the season now.
"It was an amazing achievement. They lost to Tottenham after 13 – amazing achievement. We expect a lot from them but we are ready to fight and win.
"I expect a strong reaction from them. They are old champions and they want to make up for defeat."
The Blues, meanwhile, in top spot with 49 points and five clear of Liverpool in second, lost their last league tie, 2-0 to Tottenham ahead of easing past Peterborough in an FA Cup tie, following a run of 13 top-flight victories.
Chelsea boss Antonio Conte, who became the first man to win the Barclays Premier League Manager of the Month three times in a row, said: "It's a great honour to win a third straight Manager of the Month award. It will be very difficult to win a fourth, but the most important thing is to continue to work hard."
Conte added that he has a lot of respect for Claudio Ranieri, who has helped him settle in England having shared ideas about coaching.
"Leicester is a really good team with very talented players and a great manager. The Leicester game is important as we must start to win again. It will be very tough, they have good quality."
In team news, Riyad Mahrez, Islam Slimani and Daniel Amartey are all on Africa Cup of Nations duty but recent signing Wilfred Ndidi could start after making his debut against Everton last weekend.
Leonardo Ulloa is, meanwhile, struggling with a muscular problem, but Andy King and Jamie Vardy are both available for selection.
Conte did not reveal if recalled defender Nathan Ake would be involved for the weekend's tie, but John Terry is suspended.
