Backrowers Patrick Kaufusi and Tony Williams are likely to miss the global showpiece after both were injured in Tonga's 26-24 Pacific Test win over Fiji in May.
Hooker Siliva Havili came through unscathed against the Bati but has since had undergone surgery after rupturing his pectoral.
Gold Coast Titans centre Konrad Hurrell watched on from the sideline, having last played for the Kingdom in 2015, while his former Warriors teammate Solomone Kata was also unable to add to his four test caps through injury.