Lukaku spent three years at Chelsea, but didn't get enough playing time. The Belgian hitman had loan spells at West Brom and Everton before permanently joining the Toffees back in 2014.
The 27-year old is now one of the premier strikers in world football and is currently leading Inter Milan to the Serie A title.
According to The Telegraph, Chelsea are prioritizing signing a striker in the summer, as Thomas Tuchel has lost faith in Timo Werner, Olivier Giroud and Tammy Abraham. Borussia Dortmund forward Erling Haaland tops their wish-list but he may be too expensive for the Blues.
If that is the case, the aforementioned report suggests that Thomas Tuchel's side will pursue Romelu Lukaku as an alternative, as the German coach sees the striker as a big upgrade over what Chelsea currently have.
Lukaku has been in tremendous form this season, scoring 25 goals in 34 appearances across all competitions. The Belgian would be a great signing for the Blues.
Chelsea will have to qualify for the Champions League in order to buy Lukaku
Chelsea are currently in the race for a top-4 spot in the Premier League. The Blues sit fourth in the table and have been in great form since Thomas Tuchel took over in January.
Chelsea are unbeaten in their last 15 games across all competitions and look like strong contenders to qualify for the Champions League. The Blues, however, know that if they aren't able to secure a top-4 spot, chances of landing a player of Lukaku's caliber are very slim.
Lukaku's Inter Milan are favorites to win the Scudetto this season. Antonio Conte's side are currently on top of Serie A, six points ahead of AC Milan in 2nd, with a game in hand over their rivals.
If Chelsea do not qualify for the Champions League, it would not make sense for Lukaku to leave Inter Milan in the summer as the future looks bright for the Nerazzurri.