Wales No 8 Taulupe Faletau will miss his country's first three Six Nations matches next month after suffering a calf injury, Cardiff coach Corniel van  Zyl said on Wednesday.
Faletau, 35, picked up the injury during Cardiff's United Rugby Championship defeat to the Ospreys on New Year's Day.
Wales open their campaign against England on February 7, followed by home fixtures against France on February 15 and Scotland on February 21.
"It's not clear on his return, but we're definitely looking at the middle of the Six Nations - into our Leinster game," Van  Zyl told reporters. "That is the target. We'll see how it goes."