Fabregas was lured back to the Nou Camp from Arsenal after a drawn out transfer saga in August, with many seeing the 24-year-old as a long-term replacement for Xavi rather than a partner in the same starting XI.
"We are very comfortable together on the pitch. I think we complement each other quite well," Xavi told a news conference.
"If he goes forward I stay back and cover for him or vice versa. We have shown that many times this year. I think Cesc improves my football."
Fabregas has made an immediate impact on his return to his boyhood club, after eight years in the Premier League with Arsenal, scoring four league goals in as many matches.
He has mainly been playing in a more advanced role and has quickly developed an understanding with World Player of the Year Lionel Messi and Xavi.
Xavi, who turns 32 in January, has been at the heart of the Barcelona side that has won three consecutive La Liga titles and three Champions League crowns in the last six years.
He helped Spain win Euro 2008, when he was nominated player of the tournament, and the World Cup in South Africa last year.
