New Chelsea boss Maurizio Sarri has said Manchester City coach and friend Pep Guardiola has warned him how hard the Premier League, adding that he needs to start with a trophy.
Sarri, who replaced Antonio Conte in the summer, faces Guardiola's City in the Community Shield at Wembley on Sunday.
"Guardiola told me that here in England it is very difficult," he told a news conference. "The level is very high, so he had some problems in his first season but he said that football is football everywhere.
"Sure, I think every coach at the moment wants to work here in England. The Premier League is the best level in the world. So what can I say? I can say that I am very lucky to be here."
Sarri and Guardiola spoke of their mutual respect for each other when City faced Napoli in the Champions League last season, and met for dinner with ex-AC Milan and Italy boss Arrigo Sacchi.
"We went together to visit Arrigo Sacchi so Guardiola is a friend. I think he's the best coach in the world, or one of the best for sure," Sarri added.
"The match [the Community Shield] is very difficult for one reason: they have worked together for two years and we started two-and-a-half weeks ago, so for us it will be a very difficult match."
The Chelsea job has been one of the toughest in recent years, with 13 managers having taken the helm since Roman Abramovich took over in 2003, but Sarri said there was one way to stay in the hotseat.
"I think it is very important to start with a trophy," he said. "It is important also to step forward. For me, clearly, it is important to win something.
"It depends on the club [how long I will stay]. [If] I want to stay here for 10 years, then I have to win. Then it depends on the club, but I want to stay here for a long time."