The Belgian has become the Reds' sixth summer signing after completing a €12 million move from Lille and his new boss has backed the teenager to "light up world football"
The 19-year-old becomes the club's sixth summer signing - after Emre Can, Adam Lallana, Rickie Lambert, Dejan Lovren and Lazar Markovic - but will be immediately loaned back to former side Lille for the 2014-15 season.
The Belgium international shot to prominence at the World Cup, scoring a decisive goal - his first for his country - against Russia in the group stages and Rodgers has now backed him to "light up world football".
"For me, he can be one of the most exciting talents in world football. I genuinely believe that," the Northern Irishman told Liverpool's official website.
"You see a lot of good players, but this kid - for 19 years of age - he burst onto the scene at the World Cup but we'd tracked him before that.
"He has everything to be world class. He's super fast, has a wonderful touch, he's a good size and is aggressive.
"I've seen enough of him over the course of the last couple of seasons to think this is a kid who, coming into the right environment, can genuinely be world class. He can light up world football, for sure."