Lazio's German international striker Miroslav Klose is a doubt for Sunday's derby against Roma with a knee injury, his club announced on Tuesday.
The 33-year-old was in the Germany squad for Tuesday's final Euro 2012 qualifier against Belgium, but returned to Rome on Monday for treatment.
He has injured the ligaments in his left knee and the Lazio medical staff confirmed that a decision will be made on his fitness in the next 48 hours.
The former Bayern Munich striker has already scored five goals in eight appearances for Lazio.
He is not the only big-name player at risk of missing Sunday's derby, with Roma captain Francesco Totti also a doubt because of a thigh problem.