David Luiz has described Maurizio Sarri as a "great human" and praised him for sticking to his footballing principles during Chelsea's recent struggles.
Blues head coach Sarri came under intense pressure last month following a string of poor performances and humiliating Premier League defeats at Bournemouth and Manchester City.
The 60-year-old Italian was criticised for his possession-based 'Sarri-ball' style of play and repetitive substitutions, but has since improved the club's fortunes.
"You don't change your character because of the situation, I think you change the situation," said Luiz, ahead of Thursday's Europa League last-16 first-leg clash with Dynamo Kiev.
"He's a great human, someone with the love and passion for football, someone loving with people and trying to help everybody, and trying to give the best advice.
"When you lose a game, like we did in Manchester (6-0), no one is going to be happy and coming here joking around.
"He's a real person, and real people have feelings good and bad."
After sections of the Stamford Bridge crowd jeered Sarri during the FA Cup loss to Manchester United last month, Chelsea responded with a positive performance in the Carabao Cup final before eventually losing to Manchester City on penalties.
The Blues have since beaten London rivals Tottenham and Fulham in the league to boost their hopes of Champions League qualification through a top-four finish.
Despite some modifications, Brazil defender Luiz dismissed suggestions that Sarri had dispensed with his philosophy.
And the 31-year-old also insists he and his team-mates are fully behind the tactics.
"Change the style? I don't think so, the style didn't change," he said.
"We just adapted some moments of the game, like the line to have high pressure or not.
"But our philosophy is to play from the back with possession and try to control the game.
"For many years everybody said Chelsea were winning but never controlled the game. Now we control the game and people say we don't win.
"Every player believes in his philosophy and everyone is giving 100 per cent to achieve our goals."
