Botha is suffering from an ankle injury and Tolofua with a shoulder problem.
"Given the injuries, we asked the League at the beginning of the week, about the possibility of reclassifying Servat," club president Jean-Rene Bouscatel told AFP.
Former France international Servat, 33, a three-time European champion with Toulouse, would provide emergency cover for Botha, who has been suffering from a serious recurring pain in the ankle he underwent surgery on last season.
"The only hooker that we have left is (Virgile) Lacombe," said manager Guy Noves.
Lacombe was recruited as cover for Georgian Jaba Bregvadze.