Steven Tyler

LOS ANGELES — “American Idol” is on the brink of an adolescent identity crisis.

Judge Steven Tyler is leaving and taking his naughty rock star vibe with him, fellow judge Jennifer Lopez is dithering about staying put, and ratings for the Fox show have declined as TV’s talent show field gets more competitive.

When “American Idol” returns for its 12th season next January, it will have to be a reengineered version of the once-powerhouse series that turned hopefuls such as Jennifer Hudson into stars and gave network rivals fits.

One big step would be a clean sweep of the judging panel. Aerosmith frontman Tyler got the ball rolling with his announcement Thursday that he was putting rock ‘n’ roll ahead of the show that he said had been “over-the-top fun.”

“I strayed from my first love, Aerosmith, and I’m back — but instead of begging on my hands and knees, I got two fists in the air and I’m kicking the door open with my band,” Tyler said in a statement. Aerosmith is on a nationwide tour with Tyler and has an album due out in the fall.

Tyler’s departure leaves original judge Randy Jackson and Jennifer Lopez, but their futures are cloudy.

In a phone interview with The Associated Press as the news about Tyler broke, Lopez said she was saddened to hear he was leaving and was weighing her own decision.

“I can’t even imagine anyone else there right now because I’ve just spent two years sitting next to him,” she said. “I love Steven, and we became close during that time. We were a great support for each other, on an adventure that neither one of us knew what it was going to be. So it’s hard to hear that he won’t be doing it.”

Lopez, who proved a warm charmer on “Idol,” said Tyler’s departure will play a role in her decision to stay or go. She has already indicated there is a good likelihood that she will not be back.

“All hope is never lost, not all hope, but at the same time, there are too many things that I need to think about,” she said. “I know they want me back, I know that I want to go back, but it’s not as simple as that. When I started ‘Idol’ ... I signed on for one year. I didn’t even think about doing it for two years, let alone three years.”