Randy Jackson will reportedly definitely be leaving American Idol's judging panel but sticking around as a mentor for the twelfth-season contestants.

According to sources, Idol producers had to find a way to keep Jackson on the show because he's "the glue" that keeps it together, however, they're not sure whether he's exactly fit for a mentor role, TMZ reported.

Jackson has been a judge on American Idol since its very first season premiered in 2002. The alleged decision to move him to a new mentoring position is reportedly part of the show's attempt to completely revamp the judges' table following the recent departures of Jennifer Lopez and Steven Tyler.

Mariah Carey is the only new twelfth-season judge confirmed as of yet. Nicki Minaj was reported to be finalizing an American Idol deal last week, while according to The Hollywood Reporter, country star Keith Urban is also close to inking a deal.

Regardless of whom Idol selects to come onboard the panel for the upcoming season, the show reportedly plans to have four judges for the first time since Jackson, Simon Cowell, Ellen DeGeneres and Kara DioGuardi served as the show's ninth-season panel in 2010.

According to prior reports, rapper and music producer Sean "Diddy" Combs, singer and actor Nick Jonas, singer Pharrell Williams, Latin artist Enrique Iglesias, and country singer Brad Paisley have all been considered to judge Idol's next edition -- some celebrities further along than others in the talking and negotiating process.