There's some truth to the rumors ... with UFC Hall of Famer Urijah Faber saying he'd consider coming out of retirement to fight T.J. Dillashaw -- but there are some serious caveats.
"First off, the fight for T.J. is Cody [Garbrandt]," Faber tells TMZ Sports ... insisting he doesn't want to "jump the line" and block his good friend from getting a chance to avenge his loss from UFC 217.
But if situation was right ... and the money was right ... 38-year-old Faber says he's all the way down.
And if that fight doesn't happen ... Faber says he'd considering getting back in the Octagon to fight someone else -- but it can't be a nobody.
Bottom line ... doesn't sound like we've seen the end of the California Kid.