Wales will be without Liam Williams for their 2020 Six Nations opener against Italy in Cardiff on Saturday, 1 February.
Saracens boss Mark McCall had said he expected Williams to be fit for the tournament's opening round.
But Wales boss Wayne Pivac says the full-back or wing must wait until at least the second round when they travel to Dublin to face Ireland.
Williams has not played since injuring an ankle at the 2019 World Cup.
However, there was better news for Wales fans as uncapped teenage wing Louis Rees-Zammit is scheduled to return to training on Wednesday after suffering an ankle injury playing for Gloucester last weekend at Toulouse.
Speaking at the Six Nations launch in London, Pivac said Rees-Zammit would return to his club for their English Premiership game at Bristol on Saturday.
"Louis has worked well with the medical team and he'll be back training this morning," said Pivac, who is preparing for his first Six Nations in charge.
"He'll go back to his club this weekend and we'll get him back next week.
"Liam is on for round two of the competition. He won't make the Italian match but is on track for Ireland in round two."
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