The Blues star feels that the club has lost too much experience from their Premiership-winning squad and although the current youngsters have talent, they cannot replace the know-how of the likes of Michael Ballack, Juliano Belletti, Deco, Ricardo Carvalho and Joe Cole.
"We've had a lot of injured players, and the team has changed from last year," he said.
"We lost five great players in Ballack, Belletti, Deco, Carvalho and Joe Cole.
"And we replaced them with young players like Bruma, Kakuta, McEachran and Van Aanholt.
"They are good players, but they need time to adapt."