So Serbia used their best line up in a match that was worth it nothing for both teams, but used several back up players (plus benched its main player in the tie break) in a match that was worth it a lot for Japan
Have no worry... be confident that BRA team will overcome its guest, USA, to cruise forward to Nanjing. Just make sure to win, any score will do
I ponder this year the Serbian team is very much eager to win the highest trophy of the WGP Final Six after eluding it for so many years, at least twice in 2015 & 2016 in my remembrance. In this first year of OG cycle we can see that the SRB brings its full-strength squad to the tournament... the absence of Maja is immaterial at all for the new setter, Antonijevic, is doing her task pretty well, so this is a full-powered team, the Rio Silver Medalist line-up! Thus to have one less peer competitor is not out of thought in reaching out this objective... and frankly who can complain such legitimate move
OTOH for the SRB team to throw out some little favor to the FIVB's powerhouse may prove to be somewhat wise move in the long run. Who knows one day the SRB team may need to ask some favor in return since JPN is doing lots of things for FIVB.... we all know that the island nation is the FIVB's Golden [Milking] Cow (at least in the eyes of the hi-priests there)... in a chess game the SRB's moves are all the winning ones