Ulster back-row forward, Sean Doyle, has been ruled out for up to six weeks after sustaining an undisplaced fracture of his fibula playing for Dungannon on Saturday.
The Australian-born openside flanker joined the Province in the summer and has played in three RaboDirect PRO 12 games this season.
Meanwhile, Nick Williams continues to be assessed for a rib injury he suffered in Friday night's victory over Connacht at Ravenhill.
The New Zealander was forced off with five minutes remaining in the 25 points to nil win.