Newport Gwent Dragon Thomas will be joined in the pack by lock Alun Wyn Jones after he was selected ahead of Deiniol Jones, who is among the replacements.
After remaining at home for shoulder surgery following his inspirational display in the 31-34 defeat to South Africa, James Hook is replaced by Andrew Bishop, while Scarlets scrum-half Tavis Knoyle could make his debut from the bench.
"Gavin Thomas is an experienced flanker who knows all about what it takes to perform at international level," said Wales boss Warren Gatland.
"He and Alun Wyn Jones have both impressed in training and deserve their chance this weekend.
"In the back line Andrew Bishop comes in at centre in place of James Hook who has remained in Wales to have surgery on his shoulder.
"Andrew has been one of the form centres in Wales this year and after helping the Ospreys lift the Magners League title was something of an unsung hero in their team."
Lee Byrne, Leigh Halfpenny, Andrew Bishop, Jamie Roberts, Tom Prydie, Stephen Jones, Mike Phillips, Paul James, Matthew Rees, Adam Jones, Bradley Davies, Alun Wyn Jones, Jonathan Thomas, Gavin Thomas, Ryan Jones.
Replacements: Huw Bennett, John Yapp, Deiniol Jones, Rob McCusker, Tavis Knoyle, Dan Biggar, Jonathan Davies.