Wales hooker Robin McBryde could be sidelined until November after suffering a neck injury.
The Llanelli Scarlets forward, a Lions tourist in Australia three years ago, might miss Wales autumn Tests against New Zealand, Japan and Romania as a result.
McBrydes problem has been identified as an acute prolapsed disc, although it is not thought at this stage that surgery will be required.
The 34-year-old missed Wales summer tour to Argentina and South Africa because of a shoulder injury, and the latest setback will come as a blow for new Wales coach Mike Ruddock.
Llanelli will also miss McBrydes presence, as he he is set to sit out several Celtic League games and the Scarlets opening European Cup fixtures.