IN-FORM Tongan wing Fetu'u Vainikolo could return for Connacht against The Dragons in the PRO12 League on Saturday.
Flanker Johnny O'Connor and fly-half Miah Nikora are doubts, while lock Michael Swift and centre Dave McSharry have been cleared to play.
Centres Mata Fifita and Kyle Tonetti will play in the All-Ireland League on Saturday with a view to being available for selection as the province looks to the Heineken Cup the week after this.
Winger Matt Healy, who made his debut in Dublin, suffered a hand fracture and is expected to be out of action for three to four weeks.
"We're side by side at the bottom of the table so this is a huge game for both teams. Obviously, with us at home, the pressure is on us to win it," said coach Eric Elwood.
"The key thing is that we learn from the mistakes of the last two derby matches we've had. The main focus for us is about getting everything right ourselves to secure the win."
Craig Gilroy will be fit for Ulster's top-of-the-table clash with second-placed Scarlets at Ravenhill tomorrow night.
Gilroy was considered doubtful after picking up a knee injury during Ulster's first PRO12 defeat of the season at Thomond Park last week. But, after a scan this week showed no serious damage, Gilroy was back in training ready for what stand-in captain Chris Henry says is a possible leg-up ahead of their two remaining Heineken Cup clashes at the end of the month.
FERGUS McFADDEN looks set to commit his future to Leinster and Ireland by signing a two-year contract extension with the European champions.
The 26-year-old Kildare man had attracted interest from Premiership clubs in England and Top 14 outfits in France, but looks set to remain with his native province and build on the steady improvement he has shown in recent years.
McFadden has established himself as a regular in the blue jersey in the last three seasons and has been a consistent performer this campaign in a difficult year for the province.