Kate McKinnon of The Big Gay Sketch Show is to make her debut on the April 7 episode of the NBC series, which will be hosted by Modern Family's Sofia Vergara.
Jessica Joy (The Playboy Club), Lauren Lapkus (Are You There Chelsea), Elaine Carroll (Very Mary-Kate) and three male performers have also taken screen tests in front of SNL creator Lorne Michaels, according to Deadline.
Wiig's contract runs out at the end of the current season and a decision over her future on SNL is expected to be made in the summer.
The Bridesmaids star recently admitted that she sometimes struggles with the "six-and-a-half-day week" that comes with her role.
"This year I've been an after-after sort of girl," she said. "Sometimes I need to blow off steam and go dance really hard."