According to Evening Standard, the Portuguese, who also managed Chelsea as well as in the Serie A is pleading with the Blues supporters to rally behind the tactician as the players understand his approach.
At the last count, the 60-year-old Sarri has faced an uphill task to bring to life his 'Sarri-ball' tactics in his first season at Stamford Bridge, with Chelsea on the sixth spot with 10 league matches to the end of the campaign.
But Mourinho, who experienced football management in Italian football, is confident Sarri will overcome his challenges in his second season at Chelsea.
"Italy is not an easy country," Mourinho was quoted as saying to beIN Sports.
"You learn how to deal with the press; it is very specialised, they have top commentators [with] great experience in football, the journalists are also very clever in using the emotion of football in Italy.
"Maurizio comes to England with more than 20 years of experience in football. I think he's ready, the main difficulty is imposing his style of play which is the way he always played with Napoli.
"The Premier League is the [league] where you sometimes have to lose your identity a bit to adapt to the characteristics of the game and the opponents.
"He will learn in time, the second season will be better for him."