The 20-year old Belgian striker is expecting first team football at Stamford Bridge after scoring 17 goals while on loan with West Bromwich Albion last season and believes Rooney's mooted arrival from Manchester United would only make him work harder.
"You know when you are playing for a team like Chelsea, there is going to be competition," said Lukaku.
"I like competition. Obviously, if he does sign, it could be a good partnership but it is the manager's choice.
"You have to accept that you have to work hard to make it a successful squad. If he is part of our team I will welcome him with open arms."