Alex Cuthbert will be out for "between four to six weeks" with a hamstring injury, a statement on the Cardiff Blues official website has confirmed.
The Welshman was part of the Wales side that secured the Six Nations crown with a 30-3 win over England last weekend, but he will now spend a period on the sidelines.
"Cuthbert, who helped secure the Six Nations Championship for Wales by scoring two tries against England last Saturday, suffered a grade two hamstring strain in the first thirty minutes of the match," read the statement.
The 22-year-old wing has made 18 appearances for his country.
