Mundo Deportivo says Barca are turning to the Austria star after being frustrated in negotiations with Real Betis for Junior Firpo.
Barca had seen Firpo as cover for Jordi Alba, though Betis' price is deemed too steep for a player who would not be a first-choice.
Instead, Barca are now ready to spend bigger money on a player who can compete directly with Alaba for a first team place.
Alaba, 27, fits the bill and Barca are now preparing an offer for the wing-back.
Alaba is tied to Bayern until 2021.