Barca travel to Stamford Bridge for the opening leg of their Champions League last-16 tie with the Blues, in the first meeting between the clubs since 2012.
Croatian international Rakitic told reporters in West London that Barcelona have identified Hazard as their opponents' main threat during the game.
"For me, [Hazard] is [world class]. He's maybe the most important player for Chelsea. But we know that Chelsea are not only Hazard," the 29-year-old said. "For sure, we have to be ready to stop him. We know he's really fast and goes one-against-one.
"In his last games, he's in really good form. We have to be ready for him.
"But also for the whole team. It will be a very special game tomorrow, and we have to enjoy it."