The speculation linking Lukaku with a return to Stamford Bridge was fuelled by his agent Mino Raiola, who revealed to talkSPORT that Everton have told him he can leave if 'certain' clubs are interested.
Lukaku left the Blues to join Everton in 2013, but after scoring 25 goals in 37 Premier League games this season, Chelsea are reportedly eager to re-sign him.
"Romelu is a great player so if he decides to go to Chelsea or Chelsea decide to sign him, I would be happy to see him in the dressing room in July," Courtois told Sky Sports.
"I guess if it's the right offer he might go. It's up to him to decide."
Everton have reportedly placed a £100 million price tag on the forward, who has two years left on his current contract.
Meanwhile, Chelsea star Eden Hazard could miss the start of the Premier League season after fracturing his ankle while training with the Belgium squad.
Hazard injured his right ankle while on international duty, according to the Belgian Football Association.
The RBFA confirmed on its Twitter account that Hazard twisted his ankle and subsequent scans revealed a fracture.
The 26-year old midfielder had been away with the national side as they prepared for games against the Czech Republic and a World Cup Qualifier against Estonia on June 9.
Hazard will now miss those games. It is not known how long he will be out.
Hazard was one of the stars of last season’s Premier League-winning campaign for Chelsea, scoring 16 times in 36 games.
His form has attracted the attention of Real Madrid and although he still has three years left on his contract at Stamford Bridge the player was quoted recently as saying he would consider a move to Spain if an offer was made.