Throughout this year, Bayern have been keen to tie down Alaba to an extended deal, only for negotiations to fracture after former club president Uli Hoeness described Alaba's agent as a "greedy piranha" during the talks.
Unconfirmed reports emerged that Alaba was demanding to become Bayern's highest paid player.
Since the disagreement between Hoeness and the Alaba camp, talks have quietened down.
With no deal agreed, Alaba is free to talk to clubs in January about a free transfer in the summer, while Bayern could opt to cash in on him rather than allowing him to leave for nothing.
Juventus see him as an ideal long-term replacement for current left-sided defender Giorgio Chiellini, who will turn 37 next August.
Alaba is believed to be seeking a new challenge away from Bayern - the club he has been with his entire professional career.