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."
WRU TV were on hand at the launch of a major new commercial deal with WRU and Mercedes-Benz South Wales (part of the Sinclair Group), which sees the family company become an official supplier to the Welsh Rugby Union
On the back of the recent Women's Rugby World Cup, the WRU has launched a revitalised Women's and Girls domestic seasonal structure, and the future is looking bright.
Go to www.wru.co.uk/tryourgame for more information
Roger Lewis talks to WRU TV at the announcement of a new £60 million Rugby Services Agreement (RSA) which provides a new and positive contractual relationship between the WRU and its four Regions for the next six years has been agreed.
The Welsh Rugby Union has announced a major new sponsorship deal with Gullivers Sports Travel which will make the UK's leading, and longest established, multi-sport tour operator, an Official Supplier for the rest of the decade.
Having taken part in seven World Cups as a player and coach, Liza Burgess hopes to go out in style this afternoon when Wales take on Australia in the Play-off for seventh and eighth place in the Women's Rugby World Cup in Paris.