Pretoria - Bulls loose forward Hanro Liebenberg's participation for Friday's Super Rugby clash against the Crusaders is in doubt.
Liebenberg suffered a head knock in the 28-21 win over the Waratahs at the weekend and team doctor Herman Rossouw said on Monday that a call on the player's availability would only be made later in the week.
"He didn't pass his (head injury) assessment this morning (Monday), so we will only start with his gradual return to training as of tomorrow (Tuesday)," Rossouw said.
Rossouw added that the Bulls' other injured players were making good progress.
Centre Burger Odendaal has recovered from his eye injury and is available for selection, while loose forward Tim Agaba, prop Dayan van der Westhuizen and locks Eli Snyman and Jason Jenkins have all regained full fitness and are back in training.
Friday night's clash at Loftus Versfeld is scheduled for 19:10.