Cape Town - Bulls centre Dylan Sage is set for a long period on the sidelines after fracturing his ankle during a warm-up match last weekend.
The Blitzbok was playing for the Blue Bulls XV in their SuperSport Rugby Challenge warm-up match against the Sharks in Durban - a curtain-raiser for the main Super Rugby match at Kings Park - when he broke his ankle.
Bulls team doctor Herman Rossouw said Sage would be out for up to three months.
The injury also leaves Sage's availability for the Blitzboks’ Olympic Sevens campaign in doubt, with the event scheduled for the end of July.
Another serious injury concern for the Bulls is prop Simphiwe Matanzima, who sustained a blow to the shoulder after coming off the bench against the Sharks. Rossouw said the 22-year-old could be out for between four and six weeks.
On the positive side, the Bulls were boosted by the return to training of loose forwards Marco van Staden and Muller Uys.
Van Staden, who has been struggling with a concussion, has started selective training sessions while Uys started full training.
The Bulls team to face the Stormers will be named on Thursday, with Saturday's match scheduled for 17:15.