Darren McFadden has re-injured his ankle in the Oakland Raiders' loss to the Denver Broncos.
The running back returned to action last night after four games out with a high ankle sprain.
The 25-year-old was unable to finish the game after aggravating the injury.
It is not known whether McFadden will be sidelined again as a result.
McFadden carried the ball for 52 yards yesterday and scored a touchdown.