At Hockenheim, the Enstone based team confirmed that Pastor Maldonado, backed by the powerful Venezuelan sponsor PDVSA, is staying put next year.
Frenchman Grosjean's prospects, however, looked less sure, as his manager Eric Boullier is now the boss at McLaren, and his backers Renault and Total could make way at Lotus for a new Mercedes partnership for 2015.
But Lotus deputy chief Federico Gastaldi said Grosjean, 28, might still be staying in black and gold for 2015.
"Let's be honest," he said. "Romain as a top, top driver is not happy with the 2014 season and this is mirrored by everyone at the team of course.
"We cannot confirm anything just yet as the timing will be right when we are both comfortable to announce something.
"All I can say is that it's certainly the intention for Romain to stay at Enstone and continue what has been a great partnership and working relationship," Gastaldi added.