It will be the centre's first appearance in the Championship and a home debut for the 25-year old who made his debut against Fiji last summer.
He starts on the bench as Townsend rewards the starting XV that beat France by naming an unchanged side with 11 Warriors in the 23.
Also named on the bench is Tim Swinson who made his return from injury against the Toyota Cheetahs at Scotstoun on Friday night and was recalled by the national side shortly after.
British & Irish Lions Stuart Hogg and Tommy Seymour start at full-back and on the wing respectively.
Warriors pair Peter Horne and Huw Jones make up the midfield while Finn Russell starts at fly-half.
Jonny Gray and Ryan Wilson are the Glasgow Warriors representatives in the pack.
Also named on the bench are loose-head Jamie Bhatti and scrum-half Ali Price.
Scotland
15 Stuart Hogg
14 Tommy Seymour
13 Huw Jones
12 Peter Horne
11 Sean Maitland
10 Finn Russell
9 Greig Laidlaw VICE CAPTAIN
1 Gordon Reid
2 Stuart McInally
3 Simon Berghan
4 Grant Gilchrist
5 Jonny Gray
6 John Barclay CAPTAIN
7 Hamish Watson
8 Ryan Wilson VICE CAPTAIN
Substitutes
16 Scott Lawson
17 Jamie Bhatti
18 Willem Nel
19 Tim Swinson
20 David Denton
21 Ali Price
22 Nick Grigg
23 Blair Kinghorn