Desailly told BBC Sport: “He has been one of Chelsea’s best players this season despite not playing in his best position.
“He is powerful, intelligent and good technically – all the qualities you need to do well in the Champions League.
He added: “Essien wasn’t yet a top player when he arrived. Lyon is a big club, but it’s not Milan, Barcelona or Chelsea.
“But the quality was there and has come through. He’s been fantastic.”