10 Dec, 12:23
Ireland's John Lacey will referee his first ever RBS 6 Nations match in February, while Alain Rolland is also included in the Elite Panel in what is his last season.
Best, who underwent surgery early last season for a chronic disc condition, was forced to leave the pitch after 49 minutes of Friday's one-point defeat of the Ospreys at Ravenhill, but the injury has been confirmed as soft tissue irritation.
The Ireland hooker will have ongoing treatment and assessment this week with a view to his availability for selection.
Elsewhere, Ulster centre Ian Whitten, who came off with a dead leg during the first half of the Ospreys game, has responded well to treatment.