Ulster have been dealt a big blow with the news that Tommy Bowe suffered significant damage to his knee against Northampton Saints on Saturday.
The 28-year-old has sustained lateral ligament damage to his right knee and is set to undergo surgery in the next few days to repair the damage.
Bowe, a leading contender for the Lions squad, was hurt when he landed awkwardly following an attempted tackle by Jamie Elliott on Saturday.
"At this stage it is not possible to put a timescale on how long his recovery period will be," read an Ulster statement.
"A further update on this will be issued following the surgery, when the full extent of the injury will be known."
Ulster second-row Dan Tuohy suffered a calf injury against the Saints and will be assessed on Monday, along with fly-half Paddy Jackson, who sustained a dead leg midway through the second half.