Lille are likely to sell young Belgian frontman Divock Origi to one of Europe's major clubs this summer, and losing Kalou as well would be a blow for manager Girard's chances of repeating last year's achievement of qualifying for the Champions League.
Girard expects Origi, who could be loaned back to Lille after being purchased by either Liverpool or Tottenham Hotspur, to play for the French club this term, but is less certain on Kalou's future.
He told reporters: "Divock Origi will be here this season. With regards to Salomon Kalou, it is less certain. But for now, he is at Lille."
Kalou, 28, has scored 30 goals in 65 Ligue 1 appearances for Lille since joining on a free transfer in 2012.