Edinburgh and Scotland lock Grant Gilchrist is set to miss the rest of the season after being struck with a fresh injury setback in his comeback on Friday.
Gilchrist suffered a fractured arm after coming off the bench in a 27-13 defeat to Ospreys at the Liberty Stadium and was informed that he must undergo surgery.
The 25-year-old was making his first appearance since he picked up a groin injury during the Rugby World Cup and had been tipped to play some part in the Six Nations.
Injury-plagued Gilchrist was appearing at club level for the first time since 2014 having fractured a different arm bone, but he now faces another lengthy lay-off.
A statement on the Pro12 side's website said: "Edinburgh Rugby is disappointed to report that lock Grant Glichrist sustained a fracture to a long bone in his forearm during a collision in Friday night's (19 February) Guinness PRO12 match against Ospreys at the Liberty Stadium.
"Gilchrist has seen a specialist and will undergo surgery today [Monday].
"The injury sustained is not to the same bone that required medical attention prior to Rugby World Cup 2015."