The transfer fee is known to be around €4.5m.
The 25-year-old who signed for Chelsea in 2012 from standard Liege couldn’t break into the first-team squad. He spent time on loans in the Netherlands, Turkey, Spain and with Championship side Middlesbrough.
“I assume now’s the time for me to depart, to find a place, to be my own man,” he said. “I’m married with a baby now, therefore i need stability.
“Chelsea have done amazingly for me, and for my family additionally, however it’s time for me to achieve my potential and obtain where i think I deserve to be.” he said