A place had been left open in the Edinburgh side for the centre until the eve of the first of the recent festive derbies after he did the damage in training earlier that week, but he has suffered a depressed eye socket, the prognosis for which is uncertain.
"He will be out for the foreseeable future," Michael Bradley, the club's head coach, said yesterday.
"Those things can take three to six weeks to settle down . . . so it is in the lap of the gods in relation to the Six Nations. It is in the process of settling down, so until it reaches a level that he can start training he will he held on the sidelines."
Bradley is also taking precautionary measures with Ross Ford, who captained Scotland in last season's championship.