Barcelona have announced Marcos Alonso has had successful back surgery.
The defender underwent his operation on Tuesday.
Barca confirmed: "Marcos Alonso, successfully operated on for his lumbar problems.
"The intervention was carried out by Dr. Amlie Lglise under the supervision of the Club's Medical Services, at the Sports Clinic Bordeaux Merignac. His evolution will determine availability."
It's expected Alonso will be missing for two months as he recovers.