Cardiff Blues flanker Sam Warburton could miss Wales' end-of-year Tests after suffering a a suspected fractured cheekbone in his team's loss to Leinster at the weekend.
The Wales skipper sustained the injury during a clash of heads with Leinster back-row Josh van der Flier at Cardiff Arms Park on Saturday.
The facial blow meant Warburton had to leave the field after 13 minutes and he then failed a head injury assessment which meant he was not allowed to play again.
Warburton will undergo a scan on Monday to determine the extent of the damage and if a fracture is confirmed he could be ruled out for up to eight weeks.
That would sideline him for Wales Tests against Australia, South Africa, Argentina and Japan.