Jose Mourinho insists that Chelsea are a weaker team without Didier Drogba - despite their lavish spending over the summer.
Drogba left Stamford Bridge after eight years at the club following Chelsea's Champions League victory over Bayern Munich in May, having agreed to join Chinese outfit Shanghai Shenhua.
Chelsea spent big during the summer transfer window as part of a squad overhaul, bringing in the likes of Eden Hazard and Oscar, and they currently sit atop the Premier League having yet to taste defeat.
Mourinho, who took Drogba to west London from Marseille in 2004, believes that despite their summer spending there a few players who could truly replace the Ivorian.
"I believe Drogba is the big difference for them," the Real Madrid coach told Sky Sports.
"I don't think you can replace him. You can buy top players and invest like Chelsea did, but there is only one Drogba, in the Premiership and Chelsea's history.
"Drogba means crucial moments. The final, a top match, Drogba is there. When the team is losing at home, Drogba is there.
"Chelsea will miss Drogba and Drogba will mean a few less points. But the team is good, with good players and they are European champions."