Rudiger says the Belgium superstar, who is on the verge of securing a return to the Premier League, is ‘a beast.’
Lukaku has improved a lot since he moved to Italy in 2018, having established himself as the one of the best strikers in Serie A.
He scored 24 goals in 36 league games to fire the Nerazzurri to their first Scudetto since the 2009/2010 season.
The former Manchester United and Everton man’s exploits in Italy has forced Chelsea to cough up a mammoth £97 million to secure the services of the 28-year-old and he is due to arrive in West London very soon.
In an interview with the media ahead of Chelsea’s UEFA Super Cup game against Villarreal on Wednesday, the German was asked about his soon-to-be team-mate and he said: "You can see in his body type that he is a beast.
"He's someone who is very strong and I think also he showed it in Italy over the past two years. He did very well over there. Also for his national team. He's a goalscorer and for me a top striker.
"I cannot talk about someone who is not a Chelsea player because I don't know anything," he added. "I think I said everything about him about his strengths and that he is a top class striker who loves to score goals."
