Wales international Dan Lydiate looks set to miss at least part of this season's NatWest 6 Nations after suffering a bicep injury.
Lydiate was hurt during the Ospreys' Guinness PRO14 victory over the Dragons on New Year's Eve.
Lydiate appears unlikely to be available for Wales' opening three games against Scotland, England and Ireland, but he could potentially miss the whole tournament, which starts on February 3.
Wales are already without Lydiate's fellow flanker Sam Warburton for the competition due to injury, while number eight Taulupe Faletau is recovering from knee trouble and thought unlikely to be back in action until late February or early March. Gloucester back-row forward Ross Moriarty is also sidelined through injury.
Centre Jonathan Davies, meanwhile, is another long-term absentee, having been hurt during Wales' November defeat against Australia.
Although 62 times-capped Lydiate started only one Test for Wales in 2017, he remains an integral squad member and captained his country against Georgia six weeks ago.