Prop Gareth Milasinovich will miss much of his debut season with Ulster after suffering a knee ligament injury.
The Irish-qualified forward, 26, must undergo surgery to repair the ACL tear he suffered in pre-season training.
Ulster say the injury will keep the former Worcester Warriors player out of action for approximately nine months.
Milasinovich, who can play on both sides of the scrum, was expected to provide cover for first-choice tight-head Marty Moore this season.
The South Africa-born prop qualifies for Ireland through his grandfather Norman McFarland, a former Ulster hooker.
Milasinovich was one of six new recruits for Ulster during the summer along with Ireland prop Jack McGrath from Leinster, locks Sam Carter and David O’Connor, utility back Matt Faddes from the Highlanders and Munster fly-half Bill Johnston.