AC Milan have confirmed midfielder Clarence Seedorf will be out for several weeks after tests confirmed he had pulled a hamstring.
The 35-year-old came off injured during the 4-0 win over Arsenal on Wednesday, and had to cheer his team-mates on from the sidelines.
Milan have released a statement saying they do not know how long he will be out for and that they will be conducting further tests next week.
Meanwhile, defender Philippe Mexes will miss Sunday's match against Cesena after he was diagnosed with inflammation on his knee.
Mexes was part of the team that all but assured their place in the next round of the Champions League after their first-leg win over Arsenal.
Veteran Alessandro Nesta is likely to be recalled to replace the France international and will partner Thiago Silva at the heart of the Milan defence.