Chelsea is yet to figure out the perfect use of Lukaku.
The Belgian forward joined the Blues from Inter Milan in a £105m deal in the summer window.
He found the net in his first four appearances for the club but failed to register a goal in his last four games.
Former Chelsea coach Antonio Conte who inspired Inter Milan to Serie A title glory last season believes Chelsea have failed to use Lukaku in the right way.
Conte said to Sky Sport Italia: “I think he can still do better, above all with his technique. He is already at a very high level, but a player must keep improving until the day he retires.
“During the game, there are moments when Lukaku needs to be turned on, but other than that he is one of the toughest forwards to play against, because he can do damage in any area of the pitch.
“If you have a centre-forward like that, you need to use him and I don’t think Chelsea have quite figured out how to use him yet.
“Last season, they didn’t have a proper centre-forward, so they rotated positions, whereas Romelu is a real reference point in attack. If they can figure out how to use Lukaku, then Chelsea can become the team to beat in the Champions League this season.”