Cris is facing a race against time to be fit for Lyon's second leg tie with Manchester United in the last 16 of the UEFA Champions League next Tuesday.
The Brazilian has not featured for the French champions since tearing ligaments in his right knee back in August.
He was on the bench for the 1-1 first leg draw, but after suffering a muscular inflammation in his thigh last week, he now looks unlikely to be in good enough shape to cope with the demands of facing the likes of Cristiano Ronaldo and Wayne Rooney.
"I really think that I won't be ready to face Manchester," Cris told L'Equipe.
"It's not the speed that worries me, but the rhythm because Manchester United will put pressure on us and that could give me problems.
"I may be able to play against Lille at the weekend, but I really have to think about it."