McInally came off the bench to score a try in the 28-17 home victory against France in Round 4 and has been restored to the starting XV for the Doddie Weir Cup match in Cardiff.
He comes in at hooker for Fraser Brown, who won his 50th cap in the victory against France, and will make his second start of the Championship.
Head coach Gregor Townsend has also brought in lock Sam Skinner, who steps in for Scott Cummings, and No.8 Magnus Bradbury, who replaces the ill Nick Haining.
Scotland are chasing their first victory in Cardiff since 2002 but arrive in good form following back-to-back wins against Italy and France.
“We set out this season to improve our consistency over a run of five tough games, something we have done well so far,” said Townsend.
“We’ve stayed in the fight in every game, which is a credit to how hard the players have worked in training and during the Tests.
“It’s also been encouraging to see how well the players have grown together and have taken on board the input from new coaches, Steve (Tandy) and Pieter (de Villiers), who have done a great job in their first season with the team.
“We’ve still got a lot to improve on and we’ll have to fight even harder on Saturday in Cardiff, which is one of the best and toughest places to play Test rugby.
“We have huge respect for the Welsh team, who narrowly missed out on a World Cup Final a few months ago. They are well-coached and have some outstanding players.
“It will be a fantastic occasion and one last opportunity to play to our potential in this Championship.”
Scotland team to play Wales at Principality Stadium in Cardiff
15. Stuart Hogg (Exeter Chiefs) – 76 caps – captain
14. Sean Maitland (Saracens) – 48 caps
13. Chris Harris (Gloucester) – 18 caps
12. Sam Johnson (Glasgow Warriors) – 13 caps
11. Blair Kinghorn (Edinburgh) – 21 caps
10. Adam Hastings (Glasgow Warriors) – 20 caps
9. Ali Price (Glasgow Warriors) – 32 caps
1. Rory Sutherland (Edinburgh) – 7 caps
2. Stuart McInally (Edinburgh) – 37 caps
3. Zander Fagerson (Glasgow Warriors) – 29 caps
4. Sam Skinner (Exeter Chiefs) – 7 caps
5. Grant Gilchrist (Edinburgh) – 42 caps
6. Jamie Ritchie (Edinburgh) – 18 caps
7. Hamish Watson (Edinburgh) – 32 caps
8. Magnus Bradbury (Edinburgh) – 14 caps
16. Fraser Brown (Glasgow Warriors) – 50 caps
17. Allan Dell (London Irish) – 32 caps
18. Willem Nel (Edinburgh) – 38 caps
19. Scott Cummings (Glasgow Warriors) – 12 caps
20. Matt Fagerson (Glasgow Warriors) – 6 caps
21. George Horne (Glasgow Warriors) – 13 caps
22. Duncan Weir (Worcester Warriors) – 28 caps
23. Kyle Steyn (Glasgow Warriors) – 1 cap