On Thursday, United boss David Moyes revealed that the English champions’ attempts to sign the former Arsenal captain were “ongoing” after two reported bids, one of £30 million ($38 million) had been rejected.
Martino, asked about Fabregas at a Nou Camp press conference, insisted: “If the club has signalled its refusal twice, then I signal it a third time – and so he (Fabregas) will be staying here.”
Barca vice-president Josep Maria Bartolomeu confirmed: “We are not thinking of selling Cesc.
“That United are showing interest in Cesc is normal, because he’s a great player.
“That doesn’t upset us, that makes us proud that they want one of our players.
“But whatever the offer, we won’t be selling him. We are relying on him.”
At the press conference Martino laid out his ambitions for his new team, declaring that he wanted Barca to concentrate on the dazzling style of play that has made the Catalan side great in the past.
The 50-year-old has joined Barca on a two year contract, replacing Tito Vilanova who stood down last Friday to pursue treatment for cancer.
Speaking about his aims Martino told the media: “Every side, even Barcelona which has already achieved certain moments of excellence, can always improve, and Barcelona still has things to win.
“To continue to retain a high standard of play in order to keep winning, that’s one of the questions.
“There is something with Barcelona that we’ve become used to and which has I could say dazzled us, at any rate which has struck us, that is the ability to know how to press forward and then quickly recuperate the ball.
“That’s perhaps one of the characteristics that we’re most interested in rediscovering so that Barca is a team that feels at ease attacking and which defends far from its box.”
Martino continued: “Every team, even Barcelona which has already attained certain moments of excellence, can always improve, and Barca still has things to win.
Turning to Barca’s star player Lionel Messi the Argentine said: “He will continue to play in exactly the same position. He has to feel comfortable, after that he’ll do the rest.”
He stressed he had no intention of changing Barca’s 4-3-3 format.
Martino joins Barca from Argentine outfit Newell’s Old Boys, a former club of Messi.
He has no previous managerial experience in Europe, although he did enjoy a brief spell in Spain with Tenerife as a player in 1991.
As a coach Martino won four league titles in Paraguay, and guided the national team to the 2010 World Cup quarter-finals.