For the primary recreation of their South African tour, Lions head coach Gatland has made 14 modifications to the beginning facet that beat Japan of their warm-up recreation in Edinburgh.
The one man to maintain his place is Wales and Cardiff Blues wing Josh Adams.
Rees-Zammit, who had a tremendous Guinness Six Nations as Wales received the 2021 title, is available in for his first Lions begin whereas his fellow countrymen Wyn Jones and Taulupe Faletau additionally start the sport.
Scrum-half Gareth Davies can also be in line for his Lions debut from the bench.
Scotland full-back Stuart Hogg captains the facet.
“It’s good to have arrived in Johannesburg and get the tour underway,” stated Gatland. “We had a lovely win final week up in Edinburgh, however there may be nonetheless lots we have to get proper on Saturday.
“I’ve been inspired by the best way the boys have educated this week. I really feel it’s gone up a degree from the place we had been in Jersey and we’re beginning to see a greater understanding of a few of our ways.
“There are some new participant mixtures for us to take a look at this Saturday – which is nice info for us because the Take a look at sequence approaches.
“My congratulations to all these taking part in their first recreation as a Lion and likewise to Hoggy too – who I’m positive will lead the facet by instance.”
Hogg, Adams and Rees-Zammit make up the back-three with England’s Owen Farrell and Scotland’s Chris Harris combining within the centre.
There’s an all-Scottish halfback pairing of Ali Worth and Finn Russell.
Within the forwards, Wales loosehead prop Jones is joined by hooker Jamie George and Kyle Sinckler within the entrance row.
There’s an all-English second row of Jonny Hill and Maro Itoje with No 8 Faletau joined within the back-row by Courtney Lawes and Hamish Watson.
Becoming a member of Davies on the bench are Luke Cowan-Dickie, Mako Vunipola, Zander Fagerson, Iain Henderson, Sam Simmonds, Bundee Aki and Elliot Daly.
THE LIONS v THE BRITISH & IRISH LIONS
Saturday 3 July 2021
Emirates Airline Park, Johannesburg
Kick-off: 5pm (BST)
15. Stuart Hogg – captain (Exeter Chiefs, Scotland) #783
14. Louis Rees-Zammit (Gloucester Rugby, Wales)
13. Chris Harris (Gloucester Rugby, Scotland)
12. Owen Farrell (Saracens, England) #780
11. Josh Adams (Cardiff Rugby, Wales) #836
10. Finn Russell (Racing 92, Scotland) #835
9. Ali Worth (Glasgow Warriors, Scotland) #843
1. Wyn Jones (Scarlets, Wales) #842
2. Jamie George (Saracens, England) #819
3. Kyle Sinckler (Bristol Bears, England) #814
4. Maro Itoje (Saracens, England) #825
5. Jonny Hill (Exeter Chiefs, England)
6.Courtney Lawes (Northampton Saints, England) #826
7. Hamish Watson (Edinburgh Rugby, Scotland)
8. Taulupe Faletau (Tub Rugby, Wales) #779
16. Luke Cowan-Dickie (Exeter Chiefs, England)
17. Mako Vunipola (Saracens, England) – Prop #787
18. Zander Fagerson (Glasgow Warriors, Scotland)
19. Iain Henderson (Ulster Rugby, Eire) #808
20. Sam Simmonds (Exeter Chiefs, England)
21.Gareth Davies (Scarlets, Wales)
22. Bundee Aki (Connacht Rugby, Eire) #837
23. Elliot Daly (Saracens, England) #822