Thailand lost to Italy in their last match on Sunday in the final week of the FIVB Nations League in Sofia.
The Thais lost to the Italians 25-20, 25-14, 25-14 to conclude the tournament in the Bulgarian capital with one win and three consecutive defeats. They beat South Korea and lost to the Dominican Republic and Brazil before the match on Sunday.
"Italy were a stronger team. They sent their best players to the match," Thailand coach Danai Sriwatcharamethakul said after the game.
Chatchu-on Moksri led the Thai squad with 10 points, followed by Pimpichaya Kokram with eight.
The Thai spikers ended the qualifying rounds with five wins and seven losses. But they still advanced to the finals after USA beat Germany 3-1 (25-17, 25-13, 13-25, 25-22) in Calgary, Canada, according to the Volleyball Association of Thailand.
Only the top seven teams will play in next month's finals, along with the host Turkey.