Fabregas joined the Blues from Barcelona in the summer after spending the past three years in his native Spain after his successful spell with rivals Arsenal.
He has formed a formidable partnership with Serbian midfielder Matic, with the defensive midfielder proving the perfect complement to Fabregas’s attacking guile.
"It’s called the holding role, but I don’t think he is the typical holding midfield player," said Fabregas.
"He runs a lot, he is all over the place because he loves winning battles and he loves winning the ball back. So we move quite a lot in midfield and everyone helps, but definitely Nemanja is a key player for us because his defensive attributes are really important for the team."
The Spanish midfielder also believes that the Premier League he is a part of this season is much more difficult to play in than the one he left in 2010-11.
That belief comes despite the fact that Fabregas looks set to break the competition's assists record for a single season, although it is only January. Fabregas currently needs just six more assists to break the record, with his nearest rival on just eight assists.
The player also leads the passes completed and key passes stats for the league, with the 5-0 win against Swansea seeing him become the first player in Premier League history to reach 15 assists with 16 matches still to play. However, he insists that the league is harder than the one played in with Arsenal.
"The Premier League has definitely improved since I left three years ago," he said.
"The passion is still the same - from the fans, the players. Physically it has always been a really hard league because it is so competitive, but tactically it’s now much better.”