"Supergirl" was noticeably absent from CBS' list of renewed series this past March, and now a new report The Wrap just might reveal why. According to unnamed sources close to the series, CBS president Leslie Moonves is currently negotiations with Warner Bros. chief Peter Roth -- negotiations that are coming down to the wire as CBS announces its full lineup at their upfront presentation in two weeks.

The sources close to the series say that CBS wants "Supergirl" to return, but the $3 million per-episode budget isn't justified by the show's ratings. The show debuted strong back in late October, but the ratings fell by half by the end of the season. That budget, the Wrap notes, is one of the highest ever for a freshman series.

CBS Announces Renewals, "Supergirl" Not Yet Among Them

Sources say that Moonves could end up moving "Supergirl" to the CW, a network that is equal parts CBS and Warners. Rumors have persisted for a while that "Supergirl" would move to the CW, which is already home to three other DC-based superhero shows ("Flash," "Arrow" and "Legends of Tomorrow"). If the show did switch networks, the move would most certainly come with big budget cuts. An unnamed talent rep, however, said that there is "zero fact" to the rumor of a switch to the CW.