Neymar has suffered ankle ligament damage and could be a doubt for Paris Saint-Germain's Champions League meeting with Bayern Munich.
The 31-year-old was taken off on a stretcher during PSG's thrilling 4-3 win over Lille on Sunday.
Having teed up Kylian Mbappe's opener and then scored PSG's second goal, Neymar went over on his right ankle in a challenge with Benjamin Andre early in the second half.
PSG subsequently confirmed Neymar had not suffered a fracture but instead a sprain.
On Tuesday, they announced further scans had indicated ligament damage, and Neymar must now wait until next week for a firmer timescale to be put on his recovery.
According to the United Kingdom's National Health Service, the standard recovery time for such an injury is between six and eight weeks, which would rule him out of the second leg of PSG's last-16 tie with Bayern on March 8.
PSG, who face Olympique Marseille in Ligue 1 on Sunday, head to Munich trailing 1-0 from the first leg.