The Lions were beaten 27-9 by the Springboks last Saturday following their victory in the first Test.
It means the series is tied at 1-1 and will be decided this weekend.
Wales and Lions lock Jones knows head coach Warren Gatland won’t be afraid to make changes for the game which will define the tour.
Jones is poised to play in his 12th Lions Test and the second row, who is world rugby’s most capped player, said: “Everyone is well aware that Gats will make changes.
“We have got to get up and stay together. It is still a squad effort.
“Gats is notorious for making changes and we go again.
“There has been a lot said about a wounded Springbok, but I think the Lions have taken a dent and we need to put it right.
“There will probably be an opportunity for some and I have a feeling people want to put it right. I could definitely feel that.
“We are fortunate we have got another week.
“It’s obviously going to be the biggest week of the tour. It’s the last chance to put it right.”
Wales fly-half Dan Biggar kicked three penalties for the Lions in the first half of the second Test.
But Gatland’s side failed to score after the break as South Africa crossed for tries from Makazole Mapimpi and Lukhanyo Am.
Handre Pollard kicked the rest of their points.
The Lions struggled to deal with South Africa’s kicking game and with reclaiming high balls.
It led to what was in the end a comfortable South African victory and the Springboks have been boosted by the return of Duane Vermeulen to their squad for the third Test.
Giant No 8 Vermeulen, a World Cup winner in 2019, has only just returned from ankle surgery but could end up in the frame for the third Test.
South Africa do have injury concerns over Pieter-Steph du Toit and Faf de Klerk.
South Africa head coach Jacques Nienaber said: “Duane will join us on Sunday and will be medically assessed.
“We will never risk a player who is not 100 per cent fit, but he brings experience to the squad and it will be great to have him with us.”
