Neymar could miss Paris Saint-Germain's do-or-die Champions League clash against Real Madrid next week after being diagnosed with a sprained ankle and fractured metatarsal.
PSG gave no official timetable for the Brazilian's return.
Neymar was stretchered off the pitch in tears midway through Sunday's 3-0 win over Marseille, leaving supporters with a pit in their collective stomachs.
Although manager Unai Emery said he was "optimistic" his star player would return for the second leg of PSG's last-16 clash with two-time defending champion Madrid, subsequent ultrasound and CT scans offered a much grimmer view.
There's now a distinct possibility Neymar will be unavailable for next week's reverse fixture - an especially big blow considering PSG is down 3-1 on aggregate.
With the World Cup a little more than three months away, Brazil coach Tite will also be monitoring the 26-year-old's recovery closely.
