Roma defender Juan is set to miss the rest of the season after picking up a knee ligament injury.
The Brazilian was forced off during his side's derby defeat to Lazio on Sunday with the knee problem.
Scans have shown that Juan has suffered ligament damage which will rule him out of action for up to two months.
The news is a blow for Roma boss Luis Enrique as he is already missing long-term injury victim Nicolas Burdisso.
Roma's injury problems in defence could see midfielder Daniele De Rossi being used in an unfamiliar defensive role to provide cover.