Having recently come back more than a year after sustaining an anterior cruciate ligament (ACL) tear, Madrid did not provide a potential date for the Austria captain's return after the latest setback.
Madrid visit Leganes in the Copa del Rey quarter-finals on Wednesday, followed by a league derby against Atletico Madrid at home on Saturday and a trip to Manchester City in the Champions League knockout phase playoffs on February 11th.
"Following tests carried out on our player David Alaba by Real Madrid Medical Services, he has been diagnosed with an adductor injury in his left leg. His progress is being monitored," Madrid said in a statement.
Madrid top the LaLiga standings with 49 points from 22 matches, one point ahead of second-placed Atletico.