The full-back has described his new team-mate as a "vocal striker" that adds a new unique dimension to Thomas Tuchel's forward line
Romelu Lukaku "bullies everyone he comes up against", according to Reece James, who hailed the "powerful" Chelsea frontman after his stunning debut against Arsenal.
Lukaku made his first appearance for Chelsea since rejoining the club from Inter in a £98 million ($138m) deal at Emirates Stadium on Sunday, and marked the occasion by scoring the opening goal in a 2-0 victory.
The 28-year-old was also involved in the build-up to the Blues' second, scored by James, who was hugely impressed by his new team-mate's contribution in the final third of the pitch.
What's been said?
Asked to assess Lukaku's display in the London derby clash, the England international told Premier League Productions: "What an addition to our team to have such a vocal striker like that.
"Everyone’s seen today how powerful he is and when he gets a chance, he finishes. I think he’s shown how he bullies players today.
"I can’t really think of any other players like him in the world. How strong he is and how powerful, everyone he just comes up against he bullies."
Lukaku's 'emotional' day
Lukaku has scored 260 goals across his 12-year career, including 64 in 95 outings at his last club Inter, but he ranks his first strike in a Chelsea shirt above all the others.
The former Everton and Manchester United forward told beIN Sports after the win over Arsenal: "You guys know how emotional it was today. This one is the best of the lot. Obviously, it was only a tap-in but the build up was nice so for me, this one was the best.
"It took five minutes or so to understand the movements of my team-mates but I asked a lot of questions. To be honest, this group is very, very talented and hungry.
"It was easy for me to fit in because I played this way with the Belgian national team. The coach prepared us well and we came in with confidence and got a good result."
What's next?
Lukaku and James will both be in line to feature once again when Chelsea travel to Anfield to take on Liverpool this Saturday.
Thomas Tuchel's side will then take in a rest over the international break before returning to action with a home fixture against Aston Villa on September 11.