Tonga change nine for Namibia
A schedule of three matches in 10 days has prompted the changes while history will be made as they have announced two co-captains – a Rugby World Cup first, after captain Nili Latu was sidelined with a hamstring injury.
Had Latu taken the field, his 42nd cap would have made him the most capped Tongan player.
Otai said there would be also be "tactical changes" after the Pacific Islanders were beaten 10-17 in their opening Pool C match by Georgia.
"There's always been a plan about how we take on these four games, and take into consideration the two four-day turnarounds in the upcoming games, but having said that, we also take into consideration now the situation that we're in," Otai said.
"We haven't had success in the last game against Georgia, so we're making sure that we address this game first and foremost, hence the changes. This is the team that we believe is going to do the job in the game coming up against Namibia."
After the defeat by Georgia, Tonga have turned to experience, selecting a starting XV that is both their most capped and oldest in a World Cup match, with 327 Test caps between them and an average age of 30 years and 200 days.
Aleki Lutui is the fourth oldest player in this World Cup at 37.
History of a different kind is being made by the 'Ikale Tahi, who have become the first side to name two co-captains in a World Cup match with No.8 Viliami Ma'afu and outside centre Siale Piutau sharing the honour.
Otai's reasoning is that "two people are running the show, which also enforces the need to link more between our forwards and our backs" – a role that Latu would have played.
There is a recall for loosehead prop Soane Tonga'uiha, who was left out of the match-day 23 against Georgia, and will strengthen the Tongans in the set-piece against Namibia.
Tonga'uiha is relishing the opportunity to compete for a place in the subsequent matches against their tier one opponents, Argentina and New Zealand.
"As a player, it's disappointing to be left out of the squad, but we've said from the beginning there are 31 of us and only 23 can play, so the decisions the coaches have made we all have to back that," he said.
"And obviously there's disappointment within that but when we get the opportunity to play, we have to stake a claim and prove ourselves to play the following week."
One player who will feel at home running out on the turf at Sandy Park is wing Fetu'u Vainikolo, who spent two seasons with the Exeter Chiefs before signing for Oyonnax earlier this year. Vainikolo scored the Tongans' only try against Georgia and is one of six players to retain their starting place.
Tonga: 15 Vungakoto Lilo, 14 David Halaifonua, 13 Siale Piutau (co-captain), 12 Sione Piukala, 11 Fetu'u Vainikolo, 10 Latiume Fosita, 9 Sonatane Takulua, 8 Viliami Ma'afu (co-captain), 7 Jack Ram, 6 Sione Kalamafoni, 5 Joseph Tuineau, 4 Hale T Pole, 3 Sila Puafisi, 2 Aleki Lutui, 1 Soane Tonga'uiha.
Replacements: 16 Paula Ngauamo, 17 Tevita Mailau, 18 Halani 'Aulika, 19 Tukulua Lokotui, 20 Opeti Fonua, 21 Samisoni Fisilau, 22 Kurt Morath, 23 Telusa Veainu.
Date: Tuesday, September 29
Venue: Sandy Park, Exeter
Kick-off: 16.45 (15.45 GMT, 04.45 Wednesday, September 30 TOT)
Referee: Glen Jackson (New Zealand)
Assistant referees: Chris Pollock (New Zealand), Federico Anselmi (Argentina)
TMO: Ben Skeen (New Zealand)
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