Manchester City have also made a formal approach to reunite Alaba with Pep Guardiola, who he worked with in Bavaria.
Alaba has maintained a good relationship with the Catalan coach and has previously been effusive in his praise of Guardiola.
“His training sessions are incredible workouts,” Alaba told BT Sport in 2016.
“He has reinvented football. Pep is someone who thinks about football 24 hours a day.
“With him, we have played better and better every year. I never knew that I could play in so many positions as well.”