Roma captain Francesco Totti has undergone surgery on his right knee.
The 33-year-old has missed Roma's last two Serie A matches and also their draw with Fulham in the Europa League last week.
The club confirmed Totti will start his rehabilitation on Tuesday, but it is not yet known when he will be ready to return to action.
A statement on Roma's official website read: "Today Francesco Totti underwent a medial meniscectomy arthroscopy in his right knee.
"The surgery was necessary after the player had problems during training. In the course of the surgery, no problems of any other nature (ligament or cartilage) were found.
"The player will be discharged tonight and will begin tomorrow rehabilitation. A return date will be determined depending on the player's condition."
Roma lie 12th in Serie A with 11 points from their opening nine matches.