The stroppy striker has yet to gel with the Old Trafford fans after failing to impress in the past two seasons.
But Fletcher is adamant the sulky figure on the pitch is a million miles from the cheery man in the dressing room.
And the Scot reckons his pal will come good this term.
He said: "Dimitar is a great player and has fantastic ability. I cannot see him going anywhere as he is an important part of the team.
"It is a squad game at Manchester United and he is an important part of that squad.
"He is a really good guy and I get on well with him. He is a great lad to have around the squad."
Berbatov, who has scored 26 goals in 86 outings for United, is under pressure from the next generation of Old Trafford stars.
Boss Alex Ferguson has brought in Mexican hotshot Javier Hernandez this summer and already has Federico Macheda, Danny Welbeck and Mame Biram Diouf in the ranks.
But Fletcher says the 29-year-old will be a positive influence on the young guns.
He added: "He has a lot of experience. For all our younger players and younger strikers, I am sure they can learn a lot from Dimitar."
The Red Devils take on Celtic tonight as their summer tour of the US gets underway.
And Fletcher said: "We have a lot of young players in the squad and they have a great opportunity on the tour.
"Arguably some of them could stake a claim for a place in the first team. For my part I am just going to concentrate on trying to get myself fit."