The Real Madrid forward netted a quickfire double late in the second half in Nice on Thursday, putting the result beyond all doubt after earlier strikes from Antoine Griezmann and Yohan Cabaye.
However, the 27-year-old hobbled off in the 80th minute, feeling his left thigh, and Deschamps, who said prior to kick-off that he would not substitute Benzema in response to the striker being taken off in six of his eight matches for Madrid so far this term, has admitted that early indications suggest a hamstring problem.
"Benzema has felt some great discomfort behind the thigh, [that's why] we take him off straight away," he told reporters. "I hope that it is nothing serious but we don't know yet."
Benzema has scored nine goals in total so far this season for club and country.