Lukaku, 19, has been a hit at The Hawthorns this term with 12 goals as the Baggies try to qualify for next year's Europa League.
And boss Clarke said: "If Chelsea want to loan him out for another season, I think we'd have a strong chance of getting him back.
"But it's a discussion for the summer.
"Chelsea are his parent club, he's their player and they'll decide what they want to do first and foremost. After that, hopefully we'll be able to put ourselves in the hat."