Lotus' problems look to have continued into the new season, when team boss Eric Boullier, who also doubled as Frenchman Grosjean's manager, switched to McLaren.
"It was big news and actually it surprised even us," Grosjean is quoted by France's Infosport Plus. "I think it's a big opportunity for him and I understand that.
"Now we need to find someone to replace him at Enstone, because Eric led the team very well," he added.
"We have gone through quite a difficult period," Grosjean admitted, "but now things are going much better and it's great."
Grosjean was also quoted by Le Figaro as saying that even in the midst of the problems last year, "It did not stop us from being on the podium".
"We were even the only ones who were standing up to Red Bull," he insisted. "Now the budget is balanced and everything is in place."