Lukaku will not have happy memories of his first spell at Chelsea, as he made just 10 Premier League appearances before being sold to Everton.
The Belgian failed to score in any of those outings in the top-flight, but became a reliable goal scorer for both loan club West Brom and the Toffees.
In his single season at the Hawthorns, Lukaku scored 17 goals, though he was given just two matches to replicate that form at his parent club before being sent out on loan to Everton.
He scored at least 10 top-flight goals in each of his four seasons at Goodison Park before he was sold to Manchester United, where he continued that form.
Lukaku spent just two seasons at Old Trafford before making the move to Italy, where he has once again become one of Europe’s best strikers.