The 20-year-old is currently enjoying a fine loan stint with Everton, but is expected to be recalled next summer to take up a place as a key member of Jose Mourinho’s attacking set-up.
Lukaku has developed into one of the Premier League’s most feared forwards, a reputation he gained during a season-long stint with West Brom in 2012/13.
After initially returning to Stamford Bridge, the youngster was again sent out to gain experience following the arrival of Samuel Eto’o.
While Chelsea’s current crop of attackers have failed to convince so far this term, Lukaku has been in excellent form for the Toffees, netting eight goals already.
His consistent displays have now alerted Barcelona, who are ready to offer the man dubbed ‘baby Drogba’ a big switch to the Nou Camp.
Catalan boss Tata Martino is believed to be looking to alter the club’s playing style, and sees the powerful Lukaku as the ideal man to be the focal point of a star-studded attack.
Chelsea are thought to be keen to keep the former Anderlecht ace, but rumours of a frosty relationship between the player and Mourinho have prompted speculation that a big offer may be enough to lure him away from London.