Wales have made four personnel changes to their starting line up for the Round 3 encounter at the Millennium Stadium, with injuries hitting a number of key areas, particularly the front and second rows.
Warren Gatland has to do without the likes of Gethin Jenkins, Alun Wyn Jones, Matthew Rees and Gareth Williams, as well as the suspended Andy Powell, but Thomas doesn't believe the alterations will prove problematic.
"We have strength in depth and Bradley Davies and Deiniol Jones have played well together in the big European matches for the Blues," said Thomas, after Gatland brought Davies, Jones, Richie Rees and Huw Bennett into his first XV.
"They don't get the praise they should and do a lot of the unseen work. You need players like that in any good side.
"Huw Bennett was a Grand Slam winner in 2008 so the changes should not affect us.
"France will provide a great test for us but we believe we can match them up front."
The French arrive in Cardiff on the back of successive victories over Scotland and Ireland, with many tipping them to secure a first Grand Slam since 2004.
But although Thomas respects the quality of the performances produced by France so far this year, the versatile flanker cum lock insists Wales have nothing to fear.
"France are the form team in the championship but we won't fear them," added the 27-year-old, who has made seven appearances in this season's Magners League.
"We will respect them but it has been instilled into the squad that we put in the graft and hard work - we pride ourselves on working harder than the opposition.
"We like to train and play at a high intensity and the lungs are always burning by the second half. We will make sure they are in for a tough game."
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