Leigh Halfpenny will miss Toulon's Champions Cup quarter-final with Wasps after suffering a concussion playing for Wales.
Halfpenny was forced off in the match against Italy after getting his head on the wrong side in a key tackle on the number eight Samuela Vunisa.
The concussion is Halfpenny's second in less than 12 months, meaning he must be stood down for three weeks according to reports in France.
That will keep him out of the quarter-final to be played at the Stade Mayol on April 5 in a sizeable setback for the reigning champions.
Former Wales star and pundit Jonathan Davies expressed concern for Halfpenny's career if he continues to suffer similar blows to the head.
"If he gets more and more bumps on the head, there is a danger that it's career threatening," Davies told BBC Scrum V.
"His tackling technique is poor.
"He's brave as they come. He never shirks a tackle, but I'm slightly worried now at the amount of times I see him hit his head on the wrong side.
"If you get proper tackle technique you put your head in the right place. A lot of players have had bangs on the head and then they've been told to retire and that would be a shame."