Roma full-back Cicinho looks likely to miss the UEFA Champions League tie with Arsenal and could be out for the rest of the season.
Cicinho suffered a knee injury during training on Sunday as Roma continued their preparations for Wednesday's second leg against Arsenal.
The Brazilian will undergo scans on Monday to determine the severity of the injury, but reports suggest he has damaged knee ligaments.
A club statement read: "The player sprained his right knee during training and on Monday he will undergo tests to determine the extent of the damage."
Cicinho's injury has merely added to Roma coach Luciano Spalletti's problems ahead of Arsenal's visit, with the Italians looking to overturn a one-goal deficit.
Daniele De Rossi is suspended, while Simone Perrotta and Marco Cassetti are injured, and captain Francesco Totti is a major doubt.
However, David Pizarro may be available for the game despite suffering a thigh strain during Saturday's 1-1 draw with Udinese.
Speaking after tests on the injury, the midfielder said. "I feel better than I did yesterday. We'll see."