Published Monday, 14 January 2013
Nick Williams limps off the pitch after Ulster's clash with Glasgow. (© Pacemaker)
The number eight damaged ligaments during the game at Ravenhill that saw Ulster top their pool.
It means he will miss this week's clash against Castres in France, but two of his injured teammates are likely to be back for the match.
Paddy Jackson was out with an ankle injury and Craig Gilroy, who received a bang on the head during Friday's game, are both expected to be fit for the French date.
Meanwhile it is still not known how Adam Macklin's knee injury is faring, with a decision expected to be taken on his appearance later this week.