The Ivorian midfielder is out of contract in the summer, and reportedly he is yet to open negotiations with the club over a new deal.
The Brazilian midfielder said: "He's a top player. I hope he stays.
"We want him in the side with us because he makes our life much easier.
"And, of course, he has quality. When he gets the ball, you don't know what he is capable of doing."
"He's shown his quality over the years he's been here. He's still a key player for us. We'll see what happens next season.