The Aerosmith singer let slip his role on the pop star search show following a concert in Las Vegas on Saturday night (31.07.10).
When asked what his future plans were, Tyler, 62, said: "Recording an album and I'm probably going to be judge on 'American Idol'."
He later added: "I'm doing it. What do you think? I'm doing it."
Despite his claims, 'American Idol' bosses are yet to confirm the 'I Don't Want to Miss a Thing' rocker's appointment.
Tyler's claim comes after Ellen DeGeneres quit 'American Idol', and Kara DioGuardi was fired as part of a shake-up of the series following head judge Simon Cowell's departure.
It is believed the show will return to having just three judges, with Jennifer Lopez joining Tyler and the remaining original judge Randy Jackson.
The website TMZ stated: "Sources connected with the 'American Idol' negotiations tell TMZ Kara DioGuardi has judged her last contestant on 'American Idol' - because she's been fired.
"We're told the show will be going back to a three-judge format and assuming all deals are finalised, the judge's panel will consist of Randy Jackson, Jennifer Lopez and Steven Tyler."
Singer-and-actress Lopez has reportedly been in talks with show boss Simon Fuller for several weeks.