Abidal doubtful for Sochaux clash
Abidal was absent for last weekend's 2-0 defeat to Saint-Etienne and was then hospitalised after being diagnosed with a viral infection.
The former Barcelona defender has since returned to training, but Ranieri believes the France international is still short of full fitness.
"He'll (Abidal) probably be able to do a little more today so I do not know," Ranieri said.
"But I do not think he can play."
However, the Italian was more positive over the fitness of Dimitar Berbatov, who could be in line to make his first start since his January loan move from Fulham against relegation-threatened Sochaux.
"Berbatov has improved physically, he is getting better," Ranieri added. "He may start on Saturday."
The defeat to Saint-Etienne left second-placed Monaco eight points adrift of Paris Saint-Germain following the league leaders' 2-0 win over Marseille.
Ranieri was not surprised by the setback at the Stade Geoffroy-Guichard, and is anticipating another difficult game against a Sochaux team that has won three of their last five league outings and held Monaco to a 2-2 draw in the reverse fixture back in October.
"We are in the process of competing for a major championship. If a few times we are brittle, this is normal," he added.
"I feel Sochaux will stay up. Some think it may be easy against Sochaux, I think the opposite."