Ulster will be without John Cooney and Ben Moxham for their opening Champions Cup clash in Toulouse on Saturday.
The pair were both injured in last Friday's 27-20 defeat to Leinster in the United Rugby Championship.
Veteran out-half Cooney hurt his hamstring while former Under-20 international centre Moxham's season could be over as he will require surgery on what the province called a "significant" knee injury.
Ulster hope that Zac Ward will take a full part in training later this week following his recent concussion and will be ready to face Toulouse.
Tom O'Toole and Iain Henderson are available after coming off the bench in Ireland's win over Australia last weekend.
Watch Munster v Stade Francais in the Champions Cup on Saturday from 5pm on RTÉ2 and RTÉ Player. Follow a live blog on rte.ie/sport and the RTÉ News app and listen to live commentary on RTÉ Radio 1's Saturday Sport
