Carrasso pulled a muscle in his left thigh and is currently undergoing medical tests but reports suggest it is unlikely the Bordeaux goalkeeper, third choice behind Hugo Lloris and Steve Mandanda, will be able to play any part in South Africa.
The France Football Federation were quick to reassure fans about Gallas' injury, insisting the Arsenal defender, who missed the last few weeks of the season after tearing his left calf muscle, only has a minor muscular problem after he also pulled out of training on Monday.
Gallas, France's best remaining specialist centre-back, was being assessed on Tuesday ahead of Thursday's second Group A clash with Mexico.
The 32-year-old, who has 82 international caps and was reportedly angered to be overlooked for the captaincy which went to Patrice Evra, is thought to have only experienced slight muscle discomfort.
The federation confirmed he had cut short the training session as a precautionary measure.
Gallas was partnered at the back by Barcelona's Eric Abidal, a left-back by nature who can play centrally, in the disappointing 0-0 draw with Uruguay in Cape Town on Friday.
France coach Raymond Domenech is reportedly set to restore Florent Malouda to his starting line-up having left him on the bench against Uruguay.