The Senegal international winger's future had been in doubt after he was diagnosed as having heart problems earlier this season.
"After surgery in Belgium, everything is perfect," he told BBC Sport.
"The club has asked me to sign a new contract and I'm very happy about the confidence that they have in me.
"It has been difficult for me to get a starting place because we have been playing well but I am confident that I will be in the first team next season."