The Spain midfielder has admitted that he was "very worried" about the initial challenge of adjusting to a different role at Camp Nou having been used to more freedom at Arsenal
Fabregas returned to the Catalan club in a deal worth up to €39 million last summer having joined Arsenal in 2003 after progressing through Barca's La Masia academy.
The 25-year-old has revealed that the transition back to Spanish football has not been altogether straightforward, with his form tailing off in the second half of the season following an explosive start.
Chief among the problems Fabregas has faced has been adjusting to the more disciplined role demanded of him by Pep Guardiola, having been allowed complete freedom to roam under Arsene Wenger.
"It has been a radical change in my life and like it or not it is hard to adapt," Fabregas told Spanish newspaper El Pais.
"I went from playing with complete freedom of movement to Barcelona, where the game is more positional.
"It was a challenge and I went through a period where I was very worried about it."
On a lighter note, Fabregas added defender Gerard Pique, who he grew up with at La Masia before they both made moves to English clubs, to the list of things that he had to get used to at Barcelona.
The former Manchester United centre-back is well-known as the practical joker of both the Blaugrana and the Spain national team.
"It's one of the things you have to adapt to," Fabregas joked. "It's not easy, it's been tough."
Fabregas scored the equaliser as Spain drew 1-1 with Italy in their opening match of Euro 2012 and is expected to start against the Republic of Ireland on Thursday.