The former Arsenal midfielder believes that it would be impossible to assume the veteran's role and expects the team to have to change style once he eventually hangs up his boots
The 34-year-old is adamant that he has no intention of hanging up his boots in the immediate future but has come under scrutiny during the team's poor run of form.
Fabregas has been earmarked as someone who could possibly fill the playmaking role in which Xavi has enjoyed such success but the 26-year-old thinks otherwise.
He told RAC's 'Your Say: "I don't see myself replacing Xavi. Xavi is unique.
"No matter how hard we look, Xavi is a one and only. Whoever replaces him [in the starting XI] will have to be very strong mentally and the team and the fans will have to get used to playing differently.
"The day Xavi is not in Barcelona, we will see a different team. I don't know if it'll be better or worse but it'll be different for sure."
Fabregas also stated his belief that Barcelona can complete a treble by winning La Liga, the Copa del Rey and the Champions League this season.
Gerardo Martino's men have slipped to third in the title race, four points adrift of leaders Real Madrid, following a 1-0 defeat at Real Valladolid last Saturday but bounced back by progressing in Europe with a 4-1 aggregate victory over Manchester City in the round of 16 and will contest the Copa del Rey final against Madrid in April.
"The way we played against Real Valladolid wasn't acceptable for anyone in the Barca shirt," Fabregas confessed. "It's not good for anyone that our performances can be so different in four days but we played with great discipline against City, which we didn't against Valladolid.
"I was worried that the criticism of the team would harm us but that's not how I saw it work out. I saw a team wanting to put it right.
"We will give everything [for the rest of the season] and we can win all three competitions."