Fabregas returned to boyhood club Barca in 2011 after an eight-year stint at Arsenal and he has been linked with a move back to the Premier League, with Chelsea and Manchester United keen to sign the 27-year-old midfielder.
Appearing at a promotional event in Washington, where Spain are preparing for the defence of their World Cup crown, Pique and Del Bosque were recorded apparently discussing Fabregas and a move away from Barca for a fee of €33m.
"He [Fabregas] told me that it is already done," Pique says. "He is leaving already, €33m he said," adds the centre back, who came through the youth ranks with Fabregas and is a close personal friend.
Fabregas has never fully won over the fans at Camp Nou despite scoring regularly and registering assists.