Full-back Davies picked up a knee injury in the 20-16 defeat to the Blues on Wednesday while Thomas is out of the reckoning with back trouble. The match at the Racecourse Ground in Wrexham will be the Scarlets' third outing in eight days but director of rugby Gareth Jenkins believes his squad will be able to cope.
"We've been able to balance our selection so hopefully we won't be affected too much by the injuries," he said. "We've taken a few casualties and that might pressurise our selection, but we knew this was in front of us and we were quite clear about what this week meant."
Connacht beat the Blues at home in their first game of the season, but will arrive in North Wales on the back of a 34-3 defeat to Edinburgh Gunners.
"They'll be resilient and tough, and will make life really awkward for us," added Jenkins. "They will probably be fresh and they are always capable of tripping sides up."
The annual Women's club launch was held at the Wales Centre of Excellence where National Women's Head Coach and Programme Lead Rhys Edwards, Competition Secretary Adrian Howell and Cardiff Met player Ffion Jones express eagerness for the new campaign to get under way.
WRU TV follows Wales' RWC training squad on day one of their camp in North Wales. The squad were greeted to an official welcome in Colwyn Bay and then headed for an afternoon of team building at ZipWorld