Chelsea captain John Terry has heaped praise on new signing Cesc Fabregas, claiming "most of their chances come from him opening up defences".
The Spaniard moved to Stamford Bridge earlier in the summer for a reported £26m after Arsene Wenger rejected the chance to activate the buy-back clause in the midfielder's contract.
Having played eight seasons in North London, the Spaniard has settled at Chelsea since the very beginning to orchestrate Mourinho's new midfield alongside Nemanja Matic.
Terry believes the Spaniard has been key in Chelsea's excellent start to the campaign, with the Blues topping both the Premier League and their Champions League group.
"I was delighted [when he signed]. It was a big statement getting Cesc, as well as Diego. It sent shockwaves in the Premier League," Terry said to Standard Sport.
"They have come in and both hit the ground running which is good as well. Cesc has played in the Premier League before but it can take a few weeks or months to get going but they have both started great and we are doing well at the moment."
Fabregas has already provided six assists in as many Premier League games while scoring one and giving another assist in just two Champions League appearances.
"Fabregas has made a huge impact. I know you kind of expect that from him but most of our chances come from him opening up defences. Not a lot of people can see the passes he does let alone make it", said Terry.
Having being crucial in the Champions League 1-0 victory over Sporting Lisbon by providing Matic the goal, Terry hopes for another Fabregas masterclass against his former team, Arsenal, on Sunday.
"He has been a great addition to us and long may he continue opening up defences. I don't know how much he is looking forward to playing Arsenal — you will have to ask him," Terry said.
"But we are top of the League and it's where we want to be. We want to continue playing well and stay there."