Former Chelsea star Joe Cole has no doubts about the impact summer signing Raheem Sterling will make.

At Liverpool, Cole lined up alongside C Sterling who had just gone to Anfield as a teenage wonderkid from Queens Park Rangers.

From teen star to a leader, Cole has witnessed the 27-year-old's transformation on and off the pitch.

"I played with Raheem at Liverpool," he told the London Evening Standard. "He is a great lad, really mature already as a young person, but he has grown into a fantastic player.

"He is a world class footballer. He is a quiet leader. That leadership weight of responsibility won't be too heavy for him to be the leader. I think what's important at Chelsea for Tuchel is that he is the main man.

"The players at Chelsea need to bring that togetherness to make them what they are. Raheem comes in and will offer goals, assists and leadership."