The 23-year-old Arsenal captain has been courted by the Catalan club, where he began his career, but Arsenal have spurned the La Liga champions' advances, including an offer of 29 million pounds last month.
In an interview with Catalan style magazine DIR Emotions published on Thursday, Fabregas said: "I'm a Barca fan, I'm a club member, as is my grandfather, my uncle, my cousin... I have had the colours in my blood from a young age, I'm Catalan.
"However, I'm the captain of Arsenal, I'm a 'Gunner'," he added. "And I have become a player there and matured as a person."
The attacking midfielder, a member of Spain's World Cup-winning team, had a Barca shirt forced over his head by his team mates during the players' celebration in Madrid.
Whether he dons one for real in the near future remains an open question.
Arsene Wenger said on Wednesday he had no intention of selling Fabregas and the player said his close relationship with the Arsenal manager had prompted some serious soul-searching.
He joined Arsenal as a 16-year-old in 2003 and has matured at the club, making 267 appearances and scoring 48 goals in all competitions.
"He is a second father to me, the most important person in my life after my father. He has behaved really well with me and taken me in like a son. I am part of his family," Fabregas said.
"He doesn't want me to leave. And in my last conversation with him in London, it was one of the most difficult moments I have experienced. I ended up very upset."
Fabregas is due to continue talks with Wenger over his future when he returns to the club next week.
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