Jared Payne ruled out by muscle injury
Ulster will be without Jared Payne for Friday's visit of Zebre with the Kiwi also a doubt for next week's trip to Cardiff.
Payne injured his hip-flexor muscle in the opening day draw with Scarlets on Saturday and was substituted just nine minutes into the second-half.
The soon-to-be Irish-qualified back had a scan on Monday to ascertain the extent of the damage and it is now believed he will be out of action for two weeks.
Interim Director of Rugby Les Kiss has a number of options to replace the 28-year-old, who again played outside centre at the Parc y Scarlets, with Luke Marshall, and possibly Darren Cave, available for selection.
South African Louis Ludik, primarily seen at 15, is also capable of lining up at centre in a move that would see Craig Gilroy switch from wing to full-back.
The knock to Payne is another blow for Ulster following the news lock Iain Henderson requires hip surgery and could be out of action for anything up to four months.
Henderson will therefore be absent for a sizeable portion of this season's Guinness Pro12, as well as the trip to Leicester Tigers, visit of Toulon, and double-header with Scarlets in the European Rugby Champions Cup.
With the pool stages of the revamped competition concluding just before the start of the Six Nations, the Ulster Academy product will no doubt be targeting a return in time for those important January contests if he hopes to be involved with Ireland in the spring.
Declan Fitzpatrick is another who picked up an injury at the weekend and he too may still be forced to sit out the Zebre clash.
If he is indeed absent then Ricky Lutton would most likely be promoted to the bench with new signing Wiehahn Herbst continuing to start at tighthead.
It is far from all bad news at the Kingspan Stadium however with the likes of Rory Best and Paddy Jackson set to return to the fold on Friday night.
Best – who missed the Scarlets game thanks to the Irish Player Management Programme after touring Argentina in June – is set to lead the side for the first time since being re-named Ulster captain this summer following the retirement of Johann Muller.
It remains unclear whether Cave and Tommy Bowe are also ready to return, but fly-half Jackson, who missed the trip to Argentina thanks to a back injury, is fit again and should play some part against the Italians.