'Every time you play, you are playing for your spot," he said. "It doesn't matter who you are playing, when you are in the red jersey you have got to perform if you want to play in it again.'
And the New Zealander believes Wales have their destiny in their own hands regardless of the bonus points system which has already failed group opponents Italy.
'Obviously the more they don't get the better for us, but we know we control our own destiny if we can win our first three games.
'I think they (Tonga) will throw the ball around and throw everything at us. It's win at all costs for them. If they don't get any points their tournament is all over.'
Jones, who is one of the squad's senior players and one of four nominated vice-captains, is determined to play for his place in the side.
'Nobody is given the right to play," he said. "To be selected for your country is a great honour and a huge responsibility, so if you don't perform you don't get the jersey again.
'I'm nervous, there's a will to do well. We are in a knockout situation in the World Cup, so it's do-or-die.'
In all, Hansen has made 10 changes, including two positional, to the side that overcame Canada in Wales' opening match of the Rugby World Cup for Sunday's clash with Tonga.
Prolific points scorer Stephen Jones comes into to play outside-half in a much changed back-line. Veteran centre Mark Taylor is in at outside centre and the impressive Iestyn Harris moves to the bench, allowing Sonny Parker to switch to inside centre.
Tom Shanklin replaces try-scoring wing Gareth Thomas and Rhys Williams takes Kevin Morgan's spot at full back.
In the forwards there are two changes to the front row with prop Iestyn Thomas and hooker Mefin Davies coming in for Duncan Jones and Robin McBryde. And Robert Sidoli keeps his place in the second row after appearing as a replacement for Brent Cockbain against Canada.
Finally, Alix Popham joins the back row at number 8 in place of Martyn Williams, with captain Colin Charvis moving to fill Williams' shoes at flanker.
Wales: Rhys Williams; Mark Jones, Mark Taylor, Sonny Parker, Tom Shanklin; Stephen Jones, Gareth Cooper; Iestyn Thomas, Mefin Davies, Gethin Jenkins, Gareth Llewellyn, Robert Sidoli, Dafydd Jones, Colin Charvis, Alix Popham Replacements: Huw Bennett, Adam Jones, Chris Wyatt, Martyn Williams, Dwayne Peel, Iestyn Harris, Garan Evans
Tonga: P Hola; S Fonua, S Hufanga, J Payne, T Tu'ifua; S Tu'ipulotu, S Martens; K Pulu, V Ma'asi, H Lavaka, U Latu, V Vaki, I Fenukitau, S Afeaki, B Kivalu (capt).
Replacements: E Taukafa, T Lea'aetoa, M Ngauamo, N Naufahu, D Palu, G Leger, S Va'enuku.