Rugby/Six Nations Championship: Cardiff wing Rhys Williams might miss out on Welsh rugby's biggest day since 1978 when they attempt to secure a championship clean sweep, the Triple Crown and Six Nations by beating Ireland on Saturday.

Williams, who was not born when Wales last enjoyed Grand Slam glory 27 years ago, is battling a calf muscle problem.

"Rhys aggravated an old calf muscle injury against Scotland last Sunday, really as a consequence of fatigue with the high ball-in-play time during that game," said Wales team physiotherapist Mark Davies. "We are keeping our fingers crossed, but there is a good deal of uncertainty regarding his fitness."

Hooker Mefin Davies (leg) and replacement wing Hal Luscombe (hamstring) are also receiving treatment, with coach Mike Ruddock putting back his scheduled team announcement 24 hours until lunchtime.

If Williams and Luscombe are ruled out, Ruddock could recall fit-again centre Sonny Parker and switch Tom Shanklin to the wing.

Other options would include drafting in players from outside Ruddock's current group, such as experienced Llanelli Scarlets centre Mark Taylor or Newport Gwent Dragons wing Gareth Wyatt.

Williams is doing everything possible in his fitness quest.

"I've been up every two hours, day and night, icing the injury since the game, just to give it the best chance. It is still being monitored, and I would hope to be able to train tomorrow or Thursday," he said.