Kovacic has caught the eye since joining on a season-long deal from Real Madrid in the summer transfer window.
“I think he's different class," Cole said on BT Sport.
“We know he isn't a prolific goalscorer from midfield but when you watch him closely what he does is he drives with the ball.
“Straight away that's unnerving the (opposition) back four because he's got that ability to just ghost past players.
“Cesc Fabregas is a great player but what he gives Chelsea on top of what Cesc can't do is he can drive and take players out of the game from a central midfield position.
“It allows space then for the Willians, the Eden Hazards and the Pedros to receive the ball.
“I think he's vital for the way Chelsea want to play.
“He would like to score more goals from midfield I'm sure.
“He'll be one of those players I think when he's not there, that's when you're not going to notice him.
“He drives and links the play from the defence to the attack so well."