The 29-year-old lost the Ospreys captaincy to Alun Wyn Jones over the summer and has appeared just twice as a replacement in the Magners League before coming on at half-time during the Heineken Cup defeat to Toulon.
Warren Gatland is set to name his squad on Monday after taking in the weekend's action but Jones looks to have a fight on his hands to persuade the Wales coach of his value.
But after picking both Thomas and Jones out of position, Ospreys boss Scott Johnson insists the pair are happy to sacrifice their individual ambitions for the good of the team.
"Jonathan Thomas has started the year at number eight as Ryan was unavailable for a period of time," said Johnson.
"He was asked to fill the void because of Ryan's injury and in fairness to him he has done exceptionally well.
"We needed Ryan's effectiveness and his work-rate, the team needed that, but it's too complicated to start moving everyone around.
"We are very happy with JT, and Ryan was happy to do that for the team."