After headlines all week saying Jennifer Lopez and Randy Jackson were all but gone from "American Idol," it was Steven Tyler who dropped the bomb that he was the one leaving "Idol" first.

But sources tell FOX411's Pop Tarts column that pressure from his Aerosmith bandmates to get off the show and back on tour may have been behind Tyler's abrupt departure as the show gears up of Season 12.

We're told that the promotional tour for their new album, tktk, could have clashed big time with Tyler's "Idol" Tyler commitments. Initially, the album was slated for release in August, before being pushed back to November, which is when "Idol" tryouts are in full swing. That date change could have put Tyler in the position of having to choose one or the other.

"'Idol' is a huge time commitment. I think with them moving the [Aerosmith album] to November, you can say someone really believes in it, as releasing it in the fourth quarter is superstar release time," explained Billboard writer Phil Gallo. "Promotionally it is better as well. So much of it is about having your options open."