A win over Canada would secure the Scots a place in the Churchill Cup final at the Commonwealth Stadium in Edmonton against the winner from the USA's pool which comprises of the USA, Ireland A and the New Zealand Maori.
Looking forward to the Canada clash, Bates said: "This game will be a huge test for us because it will ultimately determine whether we go home as Churchill Cup finalists or not.
"The win over England confirmed what this team is capable of and we are continuing to develop that positive mentality in our preparation for this game."
In the pack, Edinburgh Gunners duo Dickinson and Kelly come in whilst Craig Hamilton moves to the number 5 shirt to make way for Andy Hall who comes in at 4.
The pack sports an entirely fresh back-row as Reivers pair Andy Miller and Scott Gray are handed starting berths alongside Leeds Tykes No 8 Jon Dunbar.
The only changes in the back division sees Glasgow's Rory Lamont rested in place of Nikki Walker. Edinburgh's Nick De Luca is also introduced alongside Glasgow's Graeme Morrison.
Scotland A's game against Canada will be broadcast live on Sky Sports 1 from 11pm on Wednesday 7 June.
Scotland A team to play Canada in the Churchill Cup at Twin Elm Park on Wednesday 7 June (ko 6:30pm local time, 11:30pm BST)
15 Calum MacRae (Border Reivers) *
14 Simon Danielli (Border Reivers
13 Graeme Morrison (Glasgow Warriors)
12 Nick De Luca (Edinburgh Gunners) *
11 Nikki Walker (Border Reivers
10 Phil Godman (Edinburgh Gunners)
9 Rory Lawson (Edinburgh Gunners) CAPTAIN
1 Alasdair Dickinson (Edinburgh Gunners) *
2 Andrew Kelly (Edinburgh Gunners) *
3 Colin Noon (Biarritz)
4 Andy Hall (Newport-Gwent Dragons)
5 Craig Hamilton (Glasgow Warriors)
6 Scott Gray (Border Reivers)
7 Andy Miller (Border Reivers)
8 Jon Dunbar (Leeds Tykes)
Substitutes:
16 Fergus Thomson (Glasgow Warriors) *
17 Allan Jacobsen (Edinburgh Gunners)
18 Mark Rennie (Lyon)
19 Ross Beattie (Northampton Saints)
20 Alasdair Strokosch (Edinburgh Gunners) *
21 Colin Gregor (Glasgow Warriors) *
22 Rory Lamont (Glasgow Warriors)
* = Indicates member of Scottish Institute of Sport