Ulster and Ireland flanker Stephen Ferris has been ruled out for three months after further ankle surgery on Wednesday.
Ferris underwent a procedure to remove fragments of bone in his ankle but is expected to make a full recovery.
The latest setback will rule him out of contention for the Lions tour to Australia later this year.
"Ulster backrow forward, Stephen Ferris, was reviewed last week as part of his ongoing rehabilitation from an ankle injury that he sustained in November," said a statement on the club's website.
"During that review, it was discovered that although he had made excellent progress, some minor issues still remained. Those issues included function at the ankle continuing to cause pain.
"Having considered all specialist medical opinions given, Stephen underwent further ankle surgery in Belfast yesterday, during which fragments of bone were removed.
"Stephen will be out of rugby for another three months but following this period is expected to make a full and complete return to the game."