Smith is pleased to have some fledgling Premiership class on board.
"He is a player I have tried to sign on loan a couple of times previously," Smith said. "I am delighted to finally be able to bring him here.
"He's a goalscorer with tremendous pace who knows where to run and has been well-schooled in the game.
"He is highly rated at Chelsea, will certainly bring a threat and is a welcome addition to the squad."