Rhys Williams is a major doubt for the opening RBS 6 Nations game against England after picking up a shin injury.
The Wales winger was ruled out for three weeks after his club Cardiff Blues European Cup defeat to Stade Francais and is now unlikely to play before the tournament gets underway on February 5.
"He has been ruled out until the week before so it will be very tight as to whether or not he makes that game," Cardiff coach Dai Young told the Welsh Rugby Union website, wru.co.uk.
"The only consolation is that it was initially feared he would be out for up to eight weeks, which would have been just frightening for both the club and Rhys. An x-ray showed there was no break but a scan has highlighted some ligament damage."
The 24-year-old has won 40 caps and scored 14 tries for Wales though has lost his place to Newport Gwent Dragons wing Hal Luscombe since Mike Ruddock took charge.