Italy international Alessandro Florenzi could miss the rest of the season with a knee injury, his club Roma said on Friday.
The 25-year-old, who can play at full-back or in midfield, had previously ruptured his cruciate knee ligament in October and only just returned to full training.
But earlier this week, he tore the same ligament again, Roma said.
The club, currently second in Serie A, did not specify for how long Florenzi would be out but such injuries usually take at least four to six months to heal, which would mean his season is over.
A local-born player, Florenzi has often filled in as captain at Roma in the absence of club legends Francesco Totti and Daniele De Rossi. He has played 24 times for Italy.