Monique Rathbun is suing the church and its leader, David Miscavige, for allegedly harassing her and her ex-Scientologist husband, Marty.
"Who knows what may come up," Ray Jeffrey, lead counsel for the plaintiffs, told the celebrity news website.
Remini, who left the church during the summer after more than 20 years, is to give her deposition Oct. 15 while she is rehearsing for "Dancing with the Stars."
A hearing in the case is to be held Oct. 18.
Remini said at the time she left the church she did so because Scientology officials were controlling and intimidating towards its members.