Big Ben Tameifuna, who was on the fringe of All Blacks selection while with the Chiefs in the Super Rugby Championship some years back, is a key player for the Tongan side at the upcoming Rugby World Cup.
Siua Maile, Sitiveni Mafi, Tanginoa Halaifonua and Samiuela Louisi do do not step back from the challenge in tight plays and will be key for the side in set pieces.
Crusaders' Sione Havili, Moana Pasifika captain Solomone Funaki, Vaea Fifita and Sione Vailanu are key ball winners in the breakdowns and good carriers of the ball.
Good understanding between them has seen them improve and they will be the key in winning possession off the ground and in tackle-ball situations.
Veteran captain Sonatane Takulua does not back down from any challenge.
He is Tonga's most capped player having amassed 52 tests under his name.
His combination with William Havili, younger brother of All Black David Havili, will be the key to setting the experienced backline alight.
Havili has improved in the position but could face some tough challenges from both South Africa and Ireland, who like to test halves combinations with big forward charges and short interchanges directed at the number 10.
Midfield is an area where the Tongans have so much depth with Pita Ahki, Malakai Fekitoa, George Moala and Afusipa Taumoepeau all having proven themselves.
With Moala due to miss at least the first three pool matches, a lot will fall on Ahki and Fekitoa to hold that midfield together.
Former Warriors league star and Mate Ma'a Tonga strike weapon Solomone Kata is one player that could be doing more damage than expected if he gets good possession and set-ups.
A great finisher, Kata has proven to be a revelation in rugby union when he switched codes three years ago.
Tonga also has the young Kyren Taumoefolau, drafted in from the Tonga 7s team, and Moana Pasifika winger Anzelo Tuitavuki, who are both growing in their game as well.
The No.15 jersey will no doubt belong to experienced former All Black Charles Piutau.
He will be the key man in defence and they can count on him to set up counter attacks from the back.
Ireland will be the team's first match in Nantes on September 16.